Garage Door Size Calculator

Choosing the wrong garage door size means your car barely fits — or the door won't clear at all. Enter your garage width, garage height, vehicle type, and vehicle dimensions into the Garage Door Size Calculator, then select your door style and set your safety clearance and available headroom to get your recommended door width and recommended door height. Secondary outputs include side clearance, top clearance, and your door size category (e.g. single, double).

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Interior width of your garage opening

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Height from floor to ceiling

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Width of your vehicle including mirrors

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Total height of your vehicle

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Additional clearance beyond minimum requirements

inches

Space above the door opening

Results

Recommended Door Width

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Recommended Door Height

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Side Clearance

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Top Clearance

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Door Size Category

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Frequently Asked Questions

How much headroom do I need for a standard garage door?

Standard sectional garage doors require a minimum of 12 inches of headroom for proper track installation and operation. For doors with automatic openers, you may need 18-24 inches depending on the opener type.

What are standard garage door sizes?

Single garage doors are typically 8x7 feet or 9x7 feet. Double garage doors commonly measure 16x7 feet. However, custom sizes are available to fit specific garage openings and vehicle requirements.

How much clearance should I have around my vehicle?

It's recommended to have at least 6 inches of clearance on each side of your vehicle and 12 inches above. This allows for safe entry/exit and accounts for door swing and mirrors.

Can I install a larger door in my existing garage opening?

You can install a door up to the size of your garage opening, but structural modifications may be required for larger doors. Always ensure adequate headroom and side room for proper installation.

What's the difference between roll-up and sectional doors in terms of space requirements?

Roll-up doors require less headroom (typically 6-8 inches) compared to sectional doors (12+ inches) because they roll into a compact coil above the opening rather than following horizontal tracks.

How do I measure my garage opening accurately?

Measure the width and height of the rough opening (not the door frame). Take measurements at multiple points as openings may not be perfectly square, and use the smallest measurements for door sizing.

Should I consider future vehicle purchases when sizing my door?

Yes, it's wise to consider potential future vehicles. If you might upgrade to a larger SUV or truck, factor this into your door size selection to avoid costly modifications later.