SIZES

    Garage Door Sizes: Standard Widths, Heights and How to Measure

    Garage doors are sold by the size of the finished opening, not the door slab. Getting the four measurements right — width, height, headroom and backroom — is what separates a smooth installation from a change order. Here is the full size picture, from an 8-foot single to a 20-foot RV door.

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    Garage doors are sold by the size of the finished opening, not the door slab. Getting the four measurements right — width, height, headroom and backroom — is what separates a smooth installation from a change order. Here is the full size picture, from an 8-foot single to a 20-foot RV door.

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    By HG Garage Door

    Garage door service team · Canton and Metro Atlanta, Georgia.

    Last updated:

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    Standard residential sizes

    Most American homes use one of these openings, and doors in these sizes are stocked rather than special-ordered.

    • Single-car: 8' x 7', 9' x 7' (the most common of all), 8' x 8', 9' x 8'
    • Double-car: 15' x 7', 16' x 7' (the double-car standard), 18' x 7', 16' x 8', 18' x 8'
    • Taller doors: 9' x 9', 10' x 10' for trucks, vans and lifted vehicles
    • RV and oversized: 12' x 12', 14' x 14', 16' x 16', up to 20' wide custom
    • Panel height: 21 inches on standard doors, so a 7' door is four sections and an 8' door is five

    The clearances that decide feasibility

    Width and height only tell half the story. Before ordering, we check three clearances inside the garage.

    • Headroom — space above the opening to the ceiling: 12 inches standard, 4 1/2 inches minimum with low-headroom track.
    • Backroom — depth into the garage: door height plus roughly 18 inches, more with a ceiling-mounted opener.
    • Sideroom — flat wall beside the opening for vertical track: 3 3/4 inches minimum per side, 5 1/2 inches preferred.
    • Floor level — a sloped or broken slab shows as a light gap and prevents a proper seal.

    How to measure your opening correctly

    Measure the rough opening itself, not the old door and not the trim.

    • Width: at the widest point between the finished jambs, in inches.
    • Height: from the floor to the underside of the header at the center.
    • Headroom: from the top of the opening to the lowest ceiling obstruction.
    • Backroom: from the opening straight back into the garage.
    • Note any pipes, lights, storage racks or a car lift in the ceiling path.

    When a custom size is unavoidable

    Older Georgia homes, converted carports and additions often have openings that fall between standard sizes — 8'2", 15'6", 6'10" tall. Small differences are handled with jamb build-out and trim; larger gaps need a custom-width door or reframing. Send us the four numbers and we will tell you which case you are in before anything is ordered.

    Frequently Asked Questions

    What is the most common garage door size?

    9 feet wide by 7 feet tall for a single-car door, and 16 feet by 7 feet for a double-car door. Both are stocked in nearly every style and color.

    Is a 7-foot-tall door enough for a truck or SUV?

    For most stock trucks and SUVs, yes. Lifted trucks, vans with roof racks and cargo vans usually need an 8-foot door, and a full-size RV needs 12 feet or more.

    Can I fit a bigger door in my existing opening?

    Only by reframing the opening, which means structural work on the header. It is possible but it is a carpentry project first and a door project second.

    Need help choosing or repairing a door?

    HG Garage Door installs and repairs every door type in this guide across Canton and North Metro Atlanta. Call (470) 999-6963 for a free, firm quote before any work begins.

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