Guide
What is the rough opening for a garage door?
For a sectional door the rough opening is the door size exactly. Framing it wider does not give you room — it gives you a gap the seal cannot close.
A 16x7, drawn to scale. Two normal cars side by side. The most common double door in America.
| Size | Rough opening | Steel, installed |
|---|---|---|
| 16x7 | 16'0" × 7'0" | $3,240 |
| 10x10 | 10'0" × 10'0" | $5,970 |
| 8x7 | 8'0" × 7'0" | $3,170 |
| 9x7 | 9'0" × 7'0" | $3,170 |
| 10x8 | 10'0" × 8'0" | $3,170 |
| 16x8 | 16'0" × 8'0" | $3,240 |
| 12x10 | 12'0" × 10'0" | $6,390 |
| 12x12 | 12'0" × 12'0" | $6,390 |
| 10x7 | 10'0" × 7'0" | $3,170 |
| 18x7 | 18'0" × 7'0" | $3,240 |
| 18x8 | 18'0" × 8'0" | $3,240 |
| 12x7 | 12'0" × 7'0" | $3,170 |
| 20x10 | 20'0" × 10'0" | $6,390 |
| 20x8 | 20'0" × 8'0" | $6,390 |
| 20x12 | 20'0" × 12'0" | $6,390 |
Guide ranges, checked September 2026. Prices move — get it in writing.
The part that surprises people
A bigger opening barely changes the door price. On a working contractor's current list a 10x7 and a 16x7 in the same model are the same money, and an 18x8 is about $200 more. What moves the number is the model — panel style, insulation and overlay — where the same 16x8 opening runs $1,368 in basic steel, $5,163 in steel overlay and $13,428 in wood overlay.
Framing
Rough opening and clearances
For a sectional door the rough opening equals the door size exactly. A 16x7 door needs a 16'0" wide by 7'0" high finished opening.
| Clearance | Minimum | Why |
|---|---|---|
| Headroom, standard torsion | 12" | Between the top of the opening and the ceiling. |
| Headroom, low-clearance kit | 4.5" | Costs more and needs a different spring assembly. |
| Sideroom, each side | 3.75" | For the vertical track. 5.5" if the opener rail is side-mounted. |
| Backroom | door height + 18" | Add another 24" for a ceiling-mounted opener. |
Exact price
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