Guide to Garage Door Sizes

Selecting the right garage door size is an important decision when installing a new garage door or replacing an existing one. The right dimensions will ensure your garage door functions properly and provides adequate clearance for your vehicles. This comprehensive guide provides all the key information you need to determine the optimal garage door sizes for your home.

How to Measure Your Garage Door Opening

The first step in choosing the right garage door size is accurately measuring your garage door opening. Follow these steps:

  • Use a tape measure to measure the height of your opening from the floor to the top of the opening. Record this measurement.
  • Measure the width at the top, middle, and bottom of the opening. Use the narrowest width.
  • Record both measurements to determine the rough opening size. Having the exact dimensions is key for selecting the right garage door.

When measuring, make sure to measure the actual frame opening where the garage door will fit, not the garage walls themselves. You want the precise opening size, not the overall garage dimensions.

Standard Garage Door Sizes

Garage door sizes range from single car widths of 8 or 9 feet up to double car widths of 16 to 18 feet. Standard height sizes include 7 feet, 8 feet, and 10 feet.

Here are some of the most common standard garage door sizes:

  • Single car: 9 x 7 feet
  • Single car: 16 x 7 feet
  • Double car: 16 x 7 feet
  • Double car: 18 x 7 feet
  • Double car with extended height: 18 x 8 feet or 18 x 10 feet

Within these standard sizes, you’ll find options for specific door materials like wood, steel, aluminum, and fiberglass. The construction material does not usually impact the size options.

It’s also possible to get mid-range “1.5 car” sizes like 12 or 14-feet wide. If your opening falls somewhere between a single and double car, these medium sizes are a good compromise.

Why Proper Size Matters

Getting the right garage door size for your opening is about more than just aesthetics. Proper sizing impacts the operation and functionality. Here’s why it matters:

  • Fits opening snugly: A properly sized door will completely fill your opening to seal out weather and secure your garage. Gaps or overhangs compromise the seal.
  • Allows sufficient clearance: The door needs enough clearance on the sides and top to open and close without scraping. Too small and it will hit the walls or ceiling.
  • Enables proper operation: Garage door springs, rollers and other hardware are designed for specific sizes. Improper sizing can hinder smooth opening and closing.
  • Provides full access: A door that maximizes your opening width and height enables you to easily drive vehicles and move larger items in and out.

Taking accurate measurements and choosing the door to optimally fit will ensure you avoid these potential problems.

Adjusting for Floor or Ceiling Slope

Many garages have some degree of sloping along the floor or ceiling that impacts the measurements. There are a couple ways to compensate:

  • For floor sloping, measure from the highest point of the slope and use a shorter door.
  • For ceiling slope, measure from the lowest height and use a little shorter door.

Keep in mind most garage doors have about a 1-inch adjustment allowance to accommodate slopes. Make sure to account for this when measuring and selecting door size. Consulting a garage door professional is also recommended when dealing with uneven surfaces.

Custom Garage Door Sizes

Beyond the common standard sizes, custom garage doors are also an option if you have unique measurement needs. Here are some scenarios where custom sizes are useful:

  • Opening is an odd size: Older garages often have quirky dimensions that require an uncommon custom size.
  • Need to maximize height or width: Custom doors can help maximize wide or tall openings that standard sizes don’t fully fill.
  • Matching aesthetics: Custom sizes can match the look of other exterior doors on a home for a cohesive style.
  • Special vehicle sizes: Accommodating RVs, boats, buses and other large vehicles sometimes requires oversized custom garage doors.

Custom doors come at an added cost over standard sizes due to the specialty fabrication required. Lead times are also longer – often 4-6 weeks. If your opening measurements are close to a common size, opting for the standard size is usually best.

Common Garage Door Styles

Once you know your ideal garage door size, the style you select also impacts the overall look and function. Here are some of the most popular garage door styles:

Traditional Raised Panel

This classic style features inset rectangular panels that add depth for a handsome, traditional look. The panels (typically 4-6) have a raised, contoured profile.

Good for: Traditional home styles like Colonial, Craftsman, and Farmhouse designs.

Modern Flush Panel

Flush panel doors have a sleek, clean, contemporary look with no raised sections. The flat panels and minimal hardware provide a modern style.

Good for: Contemporary home styles and those wanting an updated, minimal look.

Carriage House

Carriage style doors have decorative windows across the top section. The wood trim and hardware mimic the look of old-fashioned carriage doors.

Good for: Ranch, Craftsman, Cottage style homes. The windows let in natural light.

Glass and Aluminum

These doors have large glass window panels in aluminum frames. The clear glass allows visibility and natural lighting.

Good for: Homeowners wanting an open, airy garage interior that connects to outdoor views.

The style you choose typically does not impact the size options, but it’s helpful to select once you know the ideal dimensions needed.

Factors that Influence Garage Door Size Selections

When determining the optimal garage door sizes, there are a few additional factors to keep in mind:

  • Number of cars: Choose a single or double car size based on how many vehicles you garage houses. Allow ample clearance so cars don’t hit walls.
  • Types of vehicles: If parking trucks, SUVs or other large vehicles, ensure adequate height and width.
  • Garage usage: Using the garage for workshops or storage needs wider access. Standard walk-through doors offer people entry without opening the full garage.
  • Climate weather: Insulated garage doors help prevent heat or cold loss in extreme climates. Wind load options provide added sturdiness in windy regions.
  • Budget: Door size can impact cost with larger doors and custom sizes costing more. Choose size based on specific needs.
  • Aesthetics: Proportions to the home and curb appeal are also considerations for door size choice.

Once you’ve measured your opening properly and considered these factors, you can zero in on just the right garage door size for your home and needs. Taking the time to get this right the first time will pay dividends every time you open and close your door.

Frequently Asked Questions

What is the most common garage door size?

The most common and standard garage door size is a 16 foot wide, 7 foot high double car garage door. This size is ideal for fitting two vehicles and allows easy access and clearance.

What size garage door do I need for 2 cars?

For a typical 2 car garage, an 18 foot wide by 7 foot high or 8 foot high door is recommended. This leaves ample room for two cars while still having clearance.

What is the largest size garage door?

Garage doors can be made as large as 24 feet wide by 12 feet high and higher for oversized garages. However, very large custom doors are rare and cost prohibitive for most homeowners. Most garages utilize standard 16 to 18 foot wide sizes.

Can you make a garage door smaller?

Yes, an existing garage door opening can be made smaller by having the door cut down. This involves removing sections of panels from standard sized doors. This is one solution for oversized garage doors.

How thick should a garage door be?

Modern insulated garage doors range from 1 3/8 to 2 inches thick. Thicker doors provide increased insulation and durability. Older single panel doors may be only 1 inch thick.

Can I install a smaller garage door than the opening?

It’s not recommended to install a garage door smaller than the opening size. This will lead to gaps that compromise security, weather sealing, and operation. Proper sizing for a snug fit seals better.

How much clearance do you need for a garage door?

Ideally there should be about 10 to 12 inches of clearance on each side of the door and at least 2 inches above to allow smooth operation. Any less and the door risks scraping walls and ceiling.

How much extra height does a garage door need?

Standard headroom clearance above the top of the door is about 10 to 12 inches. Low headroom garage doors require only 2-1/2 inches clearance.

How do I choose the right garage door height?

Measure the height from the floor up to the header to determine the exact frame opening height. Select a door as close to this height as possible while accounting for some floor slope.

Can you make a garage door taller?

Making an existing opening taller requires extensive structural modifications. It’s easier to match door height to the existing opening. Raising the floor with a new slab is one way to effectively increase height.

Final Considerations

Determining proper garage door sizes involves carefully measuring your existing opening, taking slope issues into account, and selecting the optimal height and width door for your needs. Standard and custom doors are available to match unique dimensions. With the right size door that fits your opening properly, you’ll enjoy maximum clearance, enhanced durability, and improved aesthetics.


Choosing new garage doors for your home is an important decision that impacts functionality, security, energy efficiency and curb appeal. Taking the time to accurately measure your opening and understand the array of size options will ensure you select the perfect garage door. This guide provides the key considerations for standard and custom doors. With these tips in mind, you can confidently choose and install garage doors with ideal dimensions for your needs. The right sized, properly fitted doors will provide years of smooth, reliable service and deliver on your vision for your home’s exterior.