How to Measure for a New Garage Door: The Complete Guide for Utah Homeowners

To measure for a new garage door, you need three key measurements: width (measure the opening at its widest point), height (measure from the floor to the top of the opening), and headroom (measure from the top of the opening to the ceiling or nearest obstruction). You’ll also need the backroom depth and side room on each side. Advanced Door, Utah’s #1 rated garage door company with a 4.9-star rating and 30,000+ reviews, provides free on-site measurements with every estimate – because accurate measurements are critical to a proper installation. We’re the only company in Utah offering a lifetime warranty on parts and labor. Family owned since 1994, serving Logan (435) 363-4929, Ogden (801) 430-9021, Draper (801) 967-8998, and all of Utah (844) 971-3667. Same-day service available.

Last updated: June 2026

Whether you’re replacing an old garage door, finishing a new build, or converting a carport into an enclosed garage, getting accurate measurements is the critical first step. An incorrectly measured garage door won’t fit properly, won’t seal against weather, and can create safety hazards that put your family at risk.

Yet most homeowners skip this step entirely or take rough measurements that lead to costly mistakes. A door ordered just one inch too wide won’t fit. A door ordered two inches too short leaves a gap that lets Utah’s winter cold, summer dust, and road salt blow straight in.

This guide walks you through every measurement you need, explains why each one matters, shows you common mistakes that lead to expensive re-orders, and helps you understand when professional measuring makes more sense than DIY. If you’d rather have a pro handle it, Advanced Door provides free on-site measurements with every estimate – call (844) 971-3667 to schedule yours.

Why Accurate Measurements Matter

Garage door measurements aren’t approximate – they’re precise. Unlike interior doors where a slightly off measurement can be shimmed or trimmed, garage doors are manufactured to exact specifications. Here’s what’s at stake:

A door that’s too wide won’t fit into the opening at all. You’ll need to return it (if the manufacturer accepts returns on custom-ordered doors) or pay to modify the framing. Either option costs hundreds of dollars and delays your project by weeks.

A door that’s too narrow leaves gaps on the sides that compromise insulation, security, and weather sealing. In Utah’s climate, those gaps let in cold air during winter, hot air during summer, dust from construction zones, and road salt that accelerates corrosion.

A door that’s too tall may not have enough headroom for the tracks, springs, and opener to fit properly. This is one of the most common measurement errors and one of the most expensive to fix.

A door that’s too short leaves a visible gap at the top that looks unprofessional and reduces energy efficiency, security, and pest protection.

Tools You’ll Need

Before you start measuring, gather these tools. The right equipment makes the difference between measurements you can trust and measurements that lead to a wrong-sized door:

• Tape measure (25-foot minimum) – A 16-foot tape won’t reach across a double garage opening without sagging. Use a rigid, locking tape measure for accuracy.
• Step ladder – You’ll need to measure headroom and check the ceiling area above the opening. A 6-foot ladder works for most residential garages.
• Level (4-foot) – To check whether your floor and opening are level. Unlevel floors are common in Utah garages, especially older homes.
• Pencil and notepad – Write down every measurement immediately. Don’t rely on memory.
• Smartphone camera – Take photos of the opening, the ceiling area, the side walls, and any obstructions. These are invaluable when discussing options with your installer.
• Flashlight – To inspect the headroom area, which is often poorly lit in residential garages.

The 5 Essential Measurements

Every garage door installation requires five key measurements. Miss any one of them and you risk ordering the wrong door or discovering on installation day that the hardware won’t fit. Here’s what you need and why:

Step-by-Step Measuring Guide

Step 1: Measure the Width

Stand inside the garage facing the door opening. Measure the width of the opening at the widest point between the inside edges of the door jambs (the vertical framing members on each side).

Critical detail: Measure in three places – at the floor, at the midpoint, and at the top of the opening. Garage door openings aren’t always perfectly square, especially in older Utah homes where settling has occurred. Record the narrowest width measurement – this is the one that matters for door sizing.

For a single-car garage, expect a width between 8 and 10 feet. For a two-car garage, expect 12 to 18 feet. If your measurement falls between standard sizes (like 8’3″ or 16’6″), you may need a custom-width door. For more on standard sizes, see our complete garage door sizes guide.

Step 2: Measure the Height

Measure the height of the opening from the garage floor to the bottom of the header (the horizontal framing member across the top of the opening). Take this measurement on both sides of the opening.

Critical detail: If the floor slopes (very common in Utah garages for drainage), measure from the highest point of the floor. The door must clear the highest point to close properly. If there’s more than a 1-inch slope across the opening, note this – your installer may need to adjust the tracks or add a threshold seal to compensate.

Standard heights are 7 feet and 8 feet. Some newer Utah homes, particularly in communities like Draper, Lehi, and Sandy, have taller 8-foot openings to accommodate trucks and SUVs.

Step 3: Measure the Headroom

This is the measurement most homeowners get wrong – and it’s the one that causes the most installation problems.

Climb your step ladder and measure from the top of the door opening (the bottom of the header) straight up to the ceiling, the bottom of any roof trusses, ductwork, plumbing, electrical panels, or any other obstruction. You need the distance to the lowest obstruction, not just the ceiling.

Minimum headroom requirements:

• Standard lift torsion spring system: 12 inches minimum
• Standard lift with opener: 15 inches minimum (opener rail needs clearance)
• Low headroom track system: As little as 4.5-6 inches (special hardware required)
• High lift system: Varies (used when you have extra headroom and want the door to track higher)

Step 4: Measure the Side Room

Measure from the edge of the door opening to the nearest side wall on each side. The vertical tracks that guide the door need mounting space on both sides.

Most standard garage door systems need at least 3.75 inches of side room on each side. If you have less, low-clearance track options exist but may limit your door choices and add cost.

Note: Also check for light switches, outlets, gas lines, water heaters, or furnaces near the opening edges. These may need to be relocated if they’re within the track zone. In Utah, many garages have the furnace or water heater positioned near the garage door opening – note its location and distance from the jamb.

Step 5: Measure the Backroom (Depth)

Measure from the inside of the door opening straight back to the rear wall of the garage (or the nearest permanent obstruction like built-in cabinets or a workbench).

The general rule: you need at least as much depth as the door height, plus 18 inches for the opener. So a 7-foot-tall door needs at least 8.5 feet of depth, and an 8-foot-tall door needs at least 9.5 feet.

If your garage is too shallow for a standard ceiling-mounted opener, a wall-mount (jackshaft) opener eliminates the rail entirely and frees up all the ceiling space.

Standard Garage Door Sizes

Garage doors come in standard sizes that most manufacturers keep in stock. Ordering a standard size means faster delivery, lower cost, and more options. Here’s what’s available:

Single-Car Garage Doors

• 8′ x 7′ – The most common single-car size. Fits most standard single-car garages built since the 1970s.
• 9′ x 7′ – Slightly wider, common in newer construction. Provides more clearance for larger vehicles.
• 9′ x 8′ – Taller version for trucks, SUVs, and vehicles with roof racks. Increasingly standard in new Utah homes.
• 10′ x 7′ or 10′ x 8′ – Oversized single for large trucks or workshop garages.

Double-Car Garage Doors

• 16′ x 7′ – The standard two-car size. By far the most common in Utah residential construction.
• 16′ x 8′ – Taller version for trucks and SUVs. Standard in most new Utah communities.
• 18′ x 7′ or 18′ x 8′ – Extra-wide double for three vehicles side by side or large vehicles with mirrors extended. See our single vs. double comparison guide for help deciding.

Non-Standard Sizes

If your opening doesn’t match a standard size, you’ll need a custom door. This is more common than you might think, particularly in:

• Older Utah homes (pre-1970s) with narrower openings
• Historic homes in Salt Lake City’s Avenues, Capitol Hill, or Sugar House neighborhoods
• Custom-built homes with non-standard architecture
• Garages converted from carports or workshops
• Commercial buildings with odd-sized openings

Custom doors typically add 2-4 weeks to the order timeline and 15-30% to the cost. But they’re the only option when your opening doesn’t match standard dimensions. For more details on what different sizes cost, see our replacement cost guide.

Special Situations and Non-Standard Openings

Low Headroom

If you have less than 12 inches of headroom above the door opening, you’ll need a low-headroom track system. These are common in garages with flat roofs, finished rooms above the garage, or HVAC ducts running close to the ceiling.

Low-headroom systems use special hardware that allows the door to operate with as little as 4.5 to 6 inches of clearance. However, they limit your opener options (wall-mount openers work best) and may restrict which door styles and weights you can use.

Measure the headroom carefully and tell your installer before they order any parts. Discovering a headroom problem on installation day means delays and extra costs.

Sloped Floors and Driveways

Many Utah garages have sloped floors for drainage, especially in areas prone to snowmelt like Ogden, Logan, and Park City. If your floor slopes across the width of the opening, the door won’t seal evenly at the bottom.

Measure the slope by placing a level across the opening at the floor. Note how much the floor drops from one side to the other. Slopes up to 1 inch can typically be handled with a flexible bottom seal. Slopes greater than 1 inch may require a custom-cut bottom panel or floor leveling.

Arched or Shaped Openings

Some carriage house style homes and custom builds have arched or shaped openings at the top. Standard garage doors are rectangular, so arched openings require either a custom arched top panel (expensive) or a decorative frame that squares off the opening and fills the arch with fixed panels.

For arched openings, measure the rectangular portion normally, then measure the arch height separately (from where the arch starts to the peak). Take a photo of the arch profile for your installer.

Obstructions Inside the Garage

Check for anything in the ceiling area that could interfere with the door tracks or opener:

• Ductwork – HVAC ducts running near the ceiling are the most common obstruction in Utah garages
• Plumbing – Water lines, drain pipes, or sprinkler system pipes
• Electrical panels – The main breaker panel is frequently mounted near the garage door opening
• Lighting – Overhead fluorescent fixtures or shop lights
• Garage door opener – If replacing a door but keeping the opener, the opener’s position affects track routing
• Storage systems – Overhead storage platforms or ceiling-mounted racks

Measure the distance from the top of the door opening to each obstruction and note its location. Your installer needs this information to plan the track layout and opener positioning.

7 Common Measuring Mistakes

These are the errors our installation teams see most often. Avoid all seven and you’ll be ahead of 90% of homeowners:

1. Measuring the existing door instead of the opening. Your current door may not be the correct size for the opening. Doors get trimmed, openings get modified, and the original builder may have used a non-standard size. Always measure the opening itself – jamb to jamb, floor to header.

2. Forgetting to measure headroom. This is the number one reason installations get delayed. Homeowners measure width and height, order a door, and then the installer discovers there’s not enough headroom for the springs, tracks, or opener. Always measure headroom before ordering anything.

3. Measuring only once and in one spot. Garage openings are rarely perfectly square or plumb, especially in older homes. Measure width in three spots (top, middle, bottom) and height on both sides. Use the smallest measurement for ordering.

4. Not checking for level. A floor that slopes 2 inches across a 16-foot opening is hard to see by eye but creates major sealing problems. Use a level. If you don’t have one, fill a garden hose with water and hold each end at the floor on opposite sides of the opening – the water levels will tell you if the floor is even.

5. Ignoring obstructions. A duct running 10 inches below the ceiling means you don’t have 14 inches of headroom – you have 10. Measure to the lowest obstruction, not just the ceiling.

6. Not measuring side room. If one side of the door opening is only 2 inches from a wall, standard tracks won’t fit. You’ll need special low-clearance hardware or may need to modify the wall. Better to know before ordering.

7. Rounding measurements. Never round up. A measurement of 8’1″ is not 8’2″ and definitely not 8’6″. Garage doors are built to precise specifications. Report measurements in feet, inches, and fractions. If your opening is 8 feet and 1.25 inches, write down exactly that.

Utah-Specific Measuring Considerations

Utah’s climate, building practices, and geography create unique measuring challenges that don’t apply in other states. Keep these in mind:

Temperature Extremes and Material Expansion

Utah’s temperature swings – from -10 degrees F in Cache Valley winters to 110 degrees F in St. George summers – cause building materials to expand and contract. This means your garage opening dimensions can change by up to 1/4 inch seasonally.

For the most accurate measurements, measure during moderate temperatures (50-70 degrees F range) when materials are closest to their “neutral” size. If you’re measuring during a Utah cold snap or heat wave, mention this to your installer so they can factor in thermal movement.

Foundation Settling in Utah Soil

Utah’s soil conditions – particularly the clay soils in the Salt Lake Valley and the expansive soils along the Wasatch Front – cause foundation settling that can shift garage openings out of square over time. Homes built on filled land (common in Lehi, Herriman, and other developing areas) are especially prone to this.

Check your opening for square by measuring diagonally from corner to corner (top-left to bottom-right, then top-right to bottom-left). If the two diagonal measurements differ by more than 1/2 inch, your opening is out of square and your installer needs to know.

Builder-Grade Garages

Utah’s construction boom from 2015-2023 produced thousands of homes with builder-grade garages that often have minimal headroom. Many builders use the cheapest possible framing, leaving barely 12 inches of headroom – just enough for a basic extension spring system but not enough for a torsion spring system or a standard opener.

If your home was built in this era, pay extra attention to headroom measurements. You may need a low-headroom track system or a wall-mount opener to make the most of limited space.

Wind Load Zones

Utah has several high-wind zones – Point of the Mountain between Draper and Lehi, canyon mouths near Ogden, and open valleys in Tooele and Spanish Fork. If you’re in a wind-prone area, you may need a wind-rated door with reinforcement struts.

Wind-rated doors are slightly thicker and heavier than standard doors, which can affect headroom requirements and spring sizing. Mention your location when getting an estimate so your installer can recommend the appropriate wind load rating.

Altitude and Garage Purpose

Utah’s higher elevations – Park City at 7,000 feet, mountain communities above 8,000 feet – can affect opener performance and spring calibration. But for measuring purposes, the biggest altitude consideration is purpose: mountain homes often use garages for more than cars.

If you plan to use the garage for workshop space, vehicle storage, or as an equipment room, consider whether you need a taller or wider door than what’s currently there. An 8-foot height lets you fit a truck with a topper. Extra width helps when storing boats, ATVs, or snowmobiles alongside vehicles.

Measuring for New Construction vs. Replacement

Replacement Doors

When replacing an existing door, you’re measuring the opening that already exists. The key questions are:

• Is the opening a standard size? (If yes, replacement is straightforward and cost-effective.)
• Is the framing in good condition? (Check for rot, rust, or structural damage to the jambs and header.)
• Do you want to change the door size? (Going bigger requires framing modifications and possibly a building permit.)
• Are you upgrading the spring system? (Switching from extension to torsion springs may require more headroom.)

For a straight replacement with the same size door, your measurements confirm the size and identify any clearance issues. For a size change, you’ll also need measurements of the surrounding wall structure to determine what modifications are feasible.

New Construction

If you’re building a new garage or doing a major remodel, you have more flexibility but also more measurements to take. The rough opening (the framed opening before drywall or trim) should be:

• Width: Door width plus 3 inches on each side (for tracks and weatherstripping)
• Height: Door height plus 1.5 to 2 inches (for header seal and leveling adjustment)
• Headroom: Plan for minimum 15 inches above the top of the opening (enough for torsion springs plus opener)
• Side room: Minimum 4 inches each side (code requirement in most Utah jurisdictions)
• Backroom: Door height plus 24 inches minimum

Commercial Garage Door Measurements

Commercial garage doors have different measurement requirements than residential doors. If you’re measuring for a warehouse, loading dock, auto shop, fire station, or agricultural building, here’s what’s different:

Width: Commercial doors range from 10 feet to over 30 feet wide. Measure the clear opening needed for your largest vehicle, equipment, or loading requirement, then add clearance for mirrors, forklifts, or traffic flow.

Height: Commercial heights range from 10 to 24+ feet. Consider the tallest vehicle or piece of equipment that needs to pass through, plus 6-12 inches of clearance.

Headroom: Commercial doors (especially rolling steel) have different headroom requirements than sectional residential doors. Rolling steel doors coil above the opening and typically need 18-24 inches of headroom. Sectional commercial doors need headroom equal to the door height.

Cycle count: Commercial doors open and close far more frequently than residential doors. When you measure, also calculate your expected daily cycles – this affects which door type, spring system, and motor your installer recommends. A car wash opening 200 times per day needs a fundamentally different system than a warehouse that opens 10 times.

DIY Measuring vs. Professional Measurement

Taking your own measurements is a great first step – it helps you understand your options, get ballpark estimates, and prepare for the installation process. But there are situations where professional measuring is worth the investment:

When DIY Measuring Is Fine

• Standard rectangular openings with no obstructions
• Replacing with the same size door (confirmation measurements)
• Getting initial estimates from multiple companies
• New construction where the architect has already specified the rough opening

When You Should Get Professional Measurements

• Non-standard or custom openings
• Low headroom situations (under 12 inches)
• Changing door size or type (going from two singles to one double, or vice versa)
• Old or settling structures where the opening may be out of square
• Switching spring types (extension to torsion)
• Commercial applications
• Any situation where you’re not 100% confident in your measurements

Advanced Door includes free on-site measurements with every estimate. Our installers carry laser measuring tools that are accurate to 1/16 of an inch and can instantly identify headroom, clearance, and squareness issues that are easy to miss with a tape measure.

Call (844) 971-3667 for a Free Measurement

What to Do After You Measure

Once you have all five measurements, here’s how to use them:

1. Check against standard sizes. If your measurements match a standard size (or are within 1/4 inch), you can order a stock door – faster delivery, lower cost, and more style options. See our sizes guide for the full list.

2. Choose your door type. Your measurements determine which door types will work. Low headroom limits your options. Narrow side room may require special tracks. The opening width and height determine the panel layout. Browse our guides on styles, brands, and how to choose.

3. Get estimates. With measurements in hand, call 2-3 companies for estimates. Accurate measurements mean accurate quotes – no “we’ll need to see it first” delays. Read our guide on why estimates differ to understand what you’re comparing.

4. Consider insulation. Your headroom measurement determines whether you can upgrade to an insulated door. Insulated doors are typically 1.5 to 2 inches thicker than non-insulated doors, which can matter in tight-headroom situations.

5. Plan for installation day. Before the crew arrives, clear the garage 5 feet back from the opening on both sides and at least 4 feet deep. Remove anything hanging from the ceiling in the track zone. Park vehicles outside. For more details, see our installation guide.

Frequently Asked Questions

What is the standard garage door size for a two-car garage?

The standard two-car garage door is 16 feet wide by 7 feet tall. Newer Utah homes often use 16′ x 8′ for additional height clearance. Some luxury homes use 18-foot-wide doors for extra clearance. Measure your actual opening rather than assuming it matches the standard – many openings are slightly different.

How much headroom do I need for a garage door?

You need a minimum of 12 inches of headroom for a standard torsion spring system, and 15 inches if you’re installing a ceiling-mounted opener. If you have less than 12 inches, low-headroom track systems can work with as little as 4.5 to 6 inches but require special hardware and may limit your door options.

Should I measure the door or the opening?

Always measure the opening – the space between the jambs and from the floor to the header. Your existing door may not match the opening size exactly, especially if it was trimmed, modified, or installed incorrectly. The opening dimensions determine what door size you need.

What if my opening isn’t square?

Check squareness by measuring diagonally from corner to corner in both directions. If the measurements differ by less than 1/2 inch, standard installation techniques can compensate. If the difference is more than 1/2 inch, the framing may need adjustment before a new door can be installed. This is common in older Utah homes with foundation settling.

Can I make my garage door opening bigger?

Yes, but it requires structural modifications to the wall framing and usually a building permit. The header (beam above the opening) must be properly sized for the wider span, and the surrounding structure must support the new loads. This is a job for a licensed contractor, not a DIY project. Contact us for a structural assessment.

How do I measure for a replacement garage door if the old door is still installed?

Measure the visible opening with the door closed. For width, measure between the inside edges of the vertical track. For height, measure from the floor to the top of the opening (where the door meets the header weatherstrip). These measurements will be very close to the actual opening dimensions. Never remove the door yourself to measure – the torsion springs are under extreme tension.

Do I need to measure differently for an insulated garage door?

Insulated doors are thicker (typically 1.375″ to 2″ for residential) than non-insulated doors (approximately 0.5″). This extra thickness rarely affects the opening measurements, but it can impact headroom. If you’re switching from a non-insulated to an insulated door, the heavier weight also requires stronger springs. Mention the upgrade to your installer.

How accurate do my measurements need to be?

Aim for accuracy within 1/4 inch on all measurements. Width and height measurements determine the door size ordered, and doors can’t be trimmed to fit. Headroom measurements within 1/2 inch are acceptable since hardware placement has some flexibility. When in doubt, report the more conservative (smaller) number and let your installer verify on site.