How much headroom does a garage door need?

It depends on the spring and track. Clopay's table gives 10 in for extension springs on 12 in radius track, 12 in on 15 in track, 12 in for torsion springs on 12 in track and 14 in on 15 in track. Wayne Dalton's torsion door manual gives 12 1/2 and 14 1/2 in. Add about 3 in for an opener on Clopay's figure, 2 1/2 in on Wayne Dalton's.

How much backroom does a garage door need?

Clopay says at least the door height plus 18 in, so 102 in for a 7 ft door, and more with an opener. Wayne Dalton's table gives 98 in for a 7 ft door lifted by hand and 125 in with a motor.

What is the rough opening for a garage door?

The same as the door size. Clopay's instructions state that the rough opening, less the stop molding, equals the door size, so a 16 by 7 door goes in a 16 by 7 opening.

How much side room does a garage door need?

Clopay asks for 3 3/4 in on each side for the vertical track and 4 1/2 in on each side above the opening for torsion springs. Wayne Dalton's manual gives a minimum side clearance of 3 1/2 in.

What ceiling height do I need for a 7 foot garage door?

The door height plus its headroom, measured to the lowest obstruction over the door. With torsion springs on 12 in track and an opener that is about 99 in, or 8 ft 3 in, on both manufacturers' figures.

Is the Wayne Dalton backroom table wrong?

One row does not convert. The 2024 manual's low headroom table prints the 7'1" to 8'0" row as 114 in and 2794 mm. 2794 mm is 110 in, the standard lift figure above it, and the 2017 edition gave 115 1/2 in for that row. Plan for the largest of the three.

How much does a new garage door cost?

HomeAdvisor's guide, updated June 2026, gives $500 to $3,000 for a one-car door, $800 to $5,000 for two-car and $1,400 to $7,200 for three-car, with an opener adding $200 to $1,300. It does not say whether the size table includes installation.

Can I install a garage door myself?

Both manufacturers publish homeowner installation manuals, and both warn repeatedly about spring tension. Clopay marks some low headroom torsion options as professional installation only.

How much does it cost to fix a broken garage door spring?

HomeAdvisor's spring repair guide gives $150 to $350 for replacing both springs on one door. Priced per broken spring, a torsion spring is $75 to $150 replaced and an extension spring $50 to $100. The torsion spring is the one both manufacturers' manuals warn about, because of the energy it stores.

How much does a single or double garage door cost?

HomeAdvisor groups them as one-car and two-car doors. A single door, 8 to 10 ft wide, is $500 to $3,000, and a double door, 16 to 20 ft wide, is $800 to $5,000. The same guide says most installers include a labor fee of $200 to $500 in the total estimate.

Do the prices change for a wood garage door or a belt drive opener?

The sources on this page do not say. HomeAdvisor's door rows are by width, one-car, two-car and three-car, with no row for a wooden door against steel, and its opener rows do not separate belt from chain drives. Its repair guide has no row for a dented panel either; the typical repair there is $155 to $379.

Does this calculator work out garage door weight?

No. It works out the opening, headroom, sideroom and backroom from the Clopay and Wayne Dalton manuals. Door weight is what the springs are set to balance, which is why both manuals warn about spring tension, and the weight of a particular door comes from its manufacturer.

How much does a single garage door cost with installation?

HomeAdvisor's June 2026 guide gives $500 to $3,000 for a one-car door 8 to 10 ft wide and $800 to $5,000 for a two-car door, with an opener adding $200 to $1,300.

How much does an overhead or 16x7 garage door cost?

HomeAdvisor's June 2026 guide gives $800 to $5,000 for a two-car overhead door 16 to 20 ft wide, which includes a 16 by 7 ft door, and $500 to $3,000 for a one-car door.

How much does a garage screen door cost?

HomeAdvisor's June 2026 guide averages a garage screen door at $900, with installation labor at $50 to $200.

Home › Windows and doors › Garage Door Size and Headroom Calculator

Garage Door Size and Headroom Calculator

Clopay and Wayne Dalton installation manuals, compared figure by figure

A garage door's rough opening is simply the door size. What decides whether it fits is the space inside: headroom above the opening, sideroom beside it and backroom behind it. Clopay and Wayne Dalton publish all three and disagree on each, by half an inch of headroom, up to an inch of sideroom and four inches of backroom. Wayne Dalton's current manual also prints one backroom figure whose inches and millimeters do not match.

The space a sectional garage door needs inside the garage

Door width

Door height, feet

Door height, extra inches

Springs

Track radius

Automatic opener

Doors in the job (for the price table below)

no.

Spring type and track radius are on the door's paperwork or can be seen on an existing door: torsion springs run along a bar above the opening, extension springs run alongside the horizontal tracks. Clopay measures radius as the curve of the track between vertical and horizontal.

Specification summary

Generated from on . Reopen that address to reproduce these figures exactly.

Entered

Result

Section through the garage at the door

Garage door prices

Per door, by size
Item	Low	High	Unit
One-car door, 8 to 10 ft wide	$500	$3,000	per door
Two-car door, 16 to 20 ft wide	$800	$5,000	per door
Three-car door, 24 to 30 ft wide	$1,400	$7,200	per door
Automatic opener	$200	$1,300	added
Installer labor fee	$200	$500	within the estimate

Source: HomeAdvisor, how much does garage door replacement cost. Last price check: September 13, 2026.

The size table is printed without a sentence saying whether it includes installation. The same guide says most installers include a labor fee of $200 to $500 in the total estimate, and gives an overall replacement range of $754 to $1,707. Its headline still reads 2025 although the page is dated June 2026. Treat the size rows as a wide bracket, not a price.

Garage door spring replacement prices

Installed unless stated
Item	Low	High	Unit
One door, both springs	$150	$350	total
Torsion spring, replaced	$75	$150	per spring
Extension spring, replaced	$50	$100	per spring
Torsion spring, part only	$30	$100	each
Extension spring, part only	$15	$45	each

Source: HomeAdvisor, how much does garage door spring repair cost. Last price check: September 13, 2026.

The source gives $150 to $350 in its headline and says most homeowners spend $75 to $500 two paragraphs later.

Garage door opener prices

As each row states
Item	Low	High	Unit
Opener, installed	$218	$540	total
Opener unit alone	$100	$900	each
Extra parts and accessories	$50	$75	total
Safety sensors	$50	$100	pair

Source: HomeAdvisor, how much does it cost to install a garage door opener. Last price check: September 13, 2026.

The opener unit alone reaches $900 in the source, above the $540 top of its own installed range.

Garage door repair prices

Per repair
Item	Low	High	Unit
Garage door repair, typical job	$155	$379	total
Reprogramming a remote	$100	$350	total
Sensor realignment	$150	$250	total
Sectional door	$150	$400	total
Tilt-up door	$150	$1,000	total
Roll-up door	$300	$800	total
One-panel door	$400	$1,200	total
Carriage door	$1,000	$10,000	total
Technician	$75	$150	per hour

Source: HomeAdvisor, how much does it cost to repair a garage door. Last price check: September 13, 2026.

The source prices reprogramming a remote at $100 to $350, most of its $155 to $379 typical repair range.

Garage door cable repair prices

Per repair
Item	Low	High	Unit
Cable repair, typical	$150	$350	total
Standard cable replacement, both cables	$150	$250	total
Cable tensioning or realignment	$100	$200	total
Partial cable repair	$150	$200	total
Complete cable system overhaul	$200	$400	total
Emergency cable repair	$250	$350	total

Source: HomeGuide, how much does garage door cable repair cost. Last price check: September 15, 2026.

The source replaces both cables together as standard, to keep the door balanced.

Worked example

A 16 by 7 foot two-car door with torsion springs on 12 inch radius track and an automatic opener. Then the same door 7'2" high without an opener.

Rough opening. The same as the door: 16 ft by 7 ft.
Headroom. Clopay 12 in plus about 3 for the opener, 15. Wayne Dalton 12 1/2 plus 2 1/2, also 15 in.
Backroom. Clopay height plus 18, 102 in, and more for the opener. Wayne Dalton's table for a motor operated 7 ft door: 125 in.
Sideroom. Clopay 3 3/4 in, Wayne Dalton 3 1/2: plan for 3 3/4 in each side.
Ceiling. 84 in of door plus 15 in of headroom: 8'3" clear over the door.
The same door at 7'2", no opener. Wayne Dalton's standard lift backroom table has no row for it; Clopay gives 104 in.

The two manuals land on the same headroom with an opener by different routes, a half inch apart on the track and a half inch apart on the opener. Without the opener they are half an inch apart, and on backroom they are not close at all.

The formula

Three spaces, each from the manufacturer, and the ceiling follows from them:

rough opening = door size backroom (Clopay) = door height + 18 in clear ceiling = door height + headroom

headroom: above the top of the opening, for the door, track and springs; more with an opener
sideroom: beside the opening on the inside wall, for the vertical track and spring brackets
backroom: from the door back into the garage, for the door fully open; more with an opener
track radius: the curve joining vertical and horizontal track, 12 or 15 in on most residential doors
low headroom: kits that cut headroom to 4 1/2 to 9 1/2 in on Clopay's table, depending on spring type

The clear ceiling figure is to the lowest thing over the door's path: a beam, a duct, a light or the opener rail, not the ceiling itself.

Why this page reads two manuals

Garage door sizing pages list standard door sizes and stop. The question a garage actually poses is whether there is room inside, and that is set by the door maker, not by the door size.

Clopay and Wayne Dalton both publish headroom, sideroom and backroom. Read side by side they differ on every figure, so the calculator shows both and plans to the larger.

Checking Wayne Dalton's metric column against its inches found one row that does not convert, whose millimeters match a different table, and a gap in its standard lift backroom table. The site publishes no price of its own.

Space inside the garage, Clopay against Wayne Dalton
Requirement	Clopay	Wayne Dalton	Difference
Headroom, torsion, 12 in radius track	12 in	12 1/2 in	1/2 in
Headroom, torsion, 15 in radius track	14 in	14 1/2 in	1/2 in
Extra headroom for an opener	about 3 in	2 1/2 in	1/2 in
Sideroom	3 3/4 in for track, 4 1/2 in above the opening for springs	3 1/2 in	1/4 to 1 in
Backroom, 7'0" door, lifted by hand	102 in (height plus 18)	98 in	4 in
Backroom, 7'0" door, with an opener	more, per the opener's instructions	125 in	not stated by Clopay

Read 2026-09-13. Clopay manual MOD 0137320-R08-1119 and Wayne Dalton REV12_01/12/2024, as printed.

Download this table as CSV. Same cells as printed above, nothing added.

The opening is the door. The room behind it is where makers differ

A garage door has no rough opening allowance. Clopay's instructions put it in one line:

Rough opening (minus stop mold) = same size as door

The door covers the opening from inside and the stop molding seals the edge. What decides whether a door fits is the space inside the garage: headroom above the opening, sideroom either side of it, and backroom behind it for the door when it is fully open.

Clopay and Wayne Dalton both publish all three, and they disagree on every one.

Space required inside the garage, as printed by each manufacturer. Difference is this page subtracting
Requirement	Clopay	Wayne Dalton	Difference
Headroom, torsion, 12 in radius track	12 in	12 1/2 in	1/2 in
Headroom, torsion, 15 in radius track	14 in	14 1/2 in	1/2 in
Extra headroom for an opener	about 3 in	2 1/2 in	1/2 in
Sideroom	3 3/4 in for track, 4 1/2 in above the opening for springs	3 1/2 in	1/4 to 1 in
Backroom, 7'0" door, lifted by hand	102 in (height plus 18)	98 in	4 in
Backroom, 7'0" door, with an opener	more, per the opener's instructions	125 in	not stated by Clopay

The gaps are small and they are the wrong size to ignore. A garage with a beam, a duct or a light over the door is usually short by inches, not feet, and half an inch of headroom decides between standard track and a low headroom kit. Plan to the larger of the two, and to the manual that ships with your door.

A manual that disagrees with its own metric column

Wayne Dalton's 2024 manual for its 8300 and 8500 doors prints backroom requirements in inches with millimeters alongside. Every figure converts correctly except one.

The low headroom table gives the 7'1" to 8'0" row as 114 in (2794 mm). 114 inches is 2,896 mm. 2794 mm is 110 inches, which is the figure in the standard lift table directly above it. The same row in the 2017 edition of the low headroom manual read 115 1/2 in (2934 mm), and those two agree with each other.

So the current manual gives three candidate answers for one row: 114 in from its inch column, 110 in from its metric column, and 115 1/2 in from its own previous edition. The largest is the safe one to plan for.

The standard lift table has a gap as well. It runs 6'0" to 7'0" and then 7'3" to 8'0", where the low headroom table beside it starts its second row at 7'1". A 7'1" or 7'2" door on standard lift track has no row. The calculator says so rather than guessing.

Standard garage door sizes, and what the size means

Garage doors are sold by the opening they close, width by height. HomeAdvisor's price guide groups them as one-car doors 8 to 10 ft wide, two-car doors 16 to 20 ft wide and three-car doors 24 to 30 ft wide, all 7 to 8 ft high.

Frame the opening to the door size. Clopay's instructions call for the inside of the opening to be framed with 2 by 6 lumber, jambs plumb and header level, with the stop molding nailed to the edges of the jambs. Wayne Dalton's manual asks for the same 2 by 6 framing and for the jambs to extend at least 12 in above the opening for torsion springs.

Two doors side by side need a post between them. Clopay's framing figure shows an 8 in minimum center post.

When the headroom is not there

Both manufacturers sell low headroom track, and Clopay's table shows how far each option cuts the requirement: to 4 1/2 in for extension springs on low headroom track, to 8 in with its quick turn bracket on 12 in radius track, and to 9 1/2 or 4 1/2 in for torsion springs mounted front or rear. Wayne Dalton's 6 in front mount low headroom track needs 8 1/2 in.

Clopay marks two of those options as professional installation only. Torsion springs store a great deal of energy, and both manuals carry repeated warnings about adjusting them. Measuring for a door is a homeowner's job; winding its springs is not.

The sources

Read 2026-09-13.

Installation Instructions, Residential Sectional Insulated Steel Doors, Clopay Corporation, MOD 0137320-R08-1119, (c) 2020, a copy of the manufacturer's manual hosted by InspectAPedia because Clopay's own document server refuses automated requests. Step 3: rough opening equal to door size, backroom of door height plus 18 in, sideroom of 3 3/4 and 4 1/2 in, Table 3-A standard headroom by spring type and track radius, Table 3-B low headroom options.

Residential Standard Lift and Front Mount Low Headroom Inside Hookup, Models 8300/8500, Wayne Dalton, a division of Overhead Door Corporation, REV12_01/12/2024, part number 350144, hosted on the manufacturer's own document store. Headroom by track radius, 2 1/2 in extra for a motor, 3 1/2 in side clearance, backroom tables for standard lift and low headroom.

Models 8300/8500 Torsion, Front Mount Low Headroom Inside Hookup, Wayne Dalton, NEW_06/01/2017, the earlier edition of the low headroom manual. Read only to compare its backroom table with the 2024 manual.

No building code sets garage door headroom or backroom. They are installation requirements of a particular door, track and spring system, and the manual that ships with your door governs. Amarr's installation documents were also sought and refused this site's requests.

Frequently asked questions

How much headroom does a garage door need?: It depends on the spring and track. Clopay's table gives 10 in for extension springs on 12 in radius track, 12 in on 15 in track, 12 in for torsion springs on 12 in track and 14 in on 15 in track. Wayne Dalton's torsion door manual gives 12 1/2 and 14 1/2 in. Add about 3 in for an opener on Clopay's figure, 2 1/2 in on Wayne Dalton's.
How much backroom does a garage door need?: Clopay says at least the door height plus 18 in, so 102 in for a 7 ft door, and more with an opener. Wayne Dalton's table gives 98 in for a 7 ft door lifted by hand and 125 in with a motor.
What is the rough opening for a garage door?: The same as the door size. Clopay's instructions state that the rough opening, less the stop molding, equals the door size, so a 16 by 7 door goes in a 16 by 7 opening.
How much side room does a garage door need?: Clopay asks for 3 3/4 in on each side for the vertical track and 4 1/2 in on each side above the opening for torsion springs. Wayne Dalton's manual gives a minimum side clearance of 3 1/2 in.
What ceiling height do I need for a 7 foot garage door?: The door height plus its headroom, measured to the lowest obstruction over the door. With torsion springs on 12 in track and an opener that is about 99 in, or 8 ft 3 in, on both manufacturers' figures.
Is the Wayne Dalton backroom table wrong?: One row does not convert. The 2024 manual's low headroom table prints the 7'1" to 8'0" row as 114 in and 2794 mm. 2794 mm is 110 in, the standard lift figure above it, and the 2017 edition gave 115 1/2 in for that row. Plan for the largest of the three.
How much does a new garage door cost?: HomeAdvisor's guide, updated June 2026, gives $500 to $3,000 for a one-car door, $800 to $5,000 for two-car and $1,400 to $7,200 for three-car, with an opener adding $200 to $1,300. It does not say whether the size table includes installation.
Can I install a garage door myself?: Both manufacturers publish homeowner installation manuals, and both warn repeatedly about spring tension. Clopay marks some low headroom torsion options as professional installation only.
How much does it cost to fix a broken garage door spring?: HomeAdvisor's spring repair guide gives $150 to $350 for replacing both springs on one door. Priced per broken spring, a torsion spring is $75 to $150 replaced and an extension spring $50 to $100. The torsion spring is the one both manufacturers' manuals warn about, because of the energy it stores.
How much does a single or double garage door cost?: HomeAdvisor groups them as one-car and two-car doors. A single door, 8 to 10 ft wide, is $500 to $3,000, and a double door, 16 to 20 ft wide, is $800 to $5,000. The same guide says most installers include a labor fee of $200 to $500 in the total estimate.
Do the prices change for a wood garage door or a belt drive opener?: The sources on this page do not say. HomeAdvisor's door rows are by width, one-car, two-car and three-car, with no row for a wooden door against steel, and its opener rows do not separate belt from chain drives. Its repair guide has no row for a dented panel either; the typical repair there is $155 to $379.
Does this calculator work out garage door weight?: No. It works out the opening, headroom, sideroom and backroom from the Clopay and Wayne Dalton manuals. Door weight is what the springs are set to balance, which is why both manuals warn about spring tension, and the weight of a particular door comes from its manufacturer.
How much does garage door spring repair cost?: HomeAdvisor's June 2026 garage door spring repair guide gives $150 to $350 to replace both springs on one door. Per spring, a torsion spring is $75 to $150 replaced and an extension spring $50 to $100, against $30 to $100 and $15 to $45 for the part alone. The same guide says most homeowners spend $75 to $500 two paragraphs after its headline.
How much does a single garage door cost with installation?: HomeAdvisor's June 2026 guide gives $500 to $3,000 for a one-car door 8 to 10 ft wide and $800 to $5,000 for a two-car door, with an opener adding $200 to $1,300.
How much does garage door cable repair cost?: HomeGuide's October 2025 guide gives $150 to $350 for a typical repair and $150 to $250 to replace both cables.
How much does an overhead or 16x7 garage door cost?: HomeAdvisor's June 2026 guide gives $800 to $5,000 for a two-car overhead door 16 to 20 ft wide, which includes a 16 by 7 ft door, and $500 to $3,000 for a one-car door.
How much does a garage screen door cost?: HomeAdvisor's June 2026 guide averages a garage screen door at $900, with installation labor at $50 to $200.

Check these numbers yourself

Installation Instructions, Residential Sectional Insulated Steel DoorsClopay Corporation, MOD 0137320-R08-1119, (c) 2020, hosted by InspectAPedia, read 2026-09-13. Step 3 headroom, backroom and sideroom, Tables 3-A and 3-B.
Residential Standard Lift and Front Mount Low Headroom Inside Hookup, Models 8300/8500Wayne Dalton, REV12_01/12/2024, part 350144, read 2026-09-13. Headroom, side clearance and backroom tables.
Models 8300/8500 Torsion, Front Mount Low Headroom Inside HookupWayne Dalton, NEW_06/01/2017, read 2026-09-13 to compare its backroom table.
How Much Does Garage Door Replacement Cost?HomeAdvisor staff writer, updated 2026-06-17, read 2026-09-13. Per door ranges by size, opener and labor fee.

How every figure here is verified: Sources & Method. Who builds this: Lucas Pradella, and the method is on About. Found something wrong? Tell us and it gets fixed or removed.

Figures on this page last checked against the source documents on 2026-09-13. Codes are amended locally; confirm against the edition your jurisdiction enforces.

Related calculators

Space requirements are quoted from two manufacturers' installation manuals, read on 13 September 2026. The manual that ships with your door governs, and figures change with model, track, spring and opener. Torsion springs are under high tension; follow the manufacturer's warnings. Prices are HomeAdvisor's, not this site's.