Doors & hardware
Door Size Converter
Type a door width and height as feet and inches, like 3 ft 0 in by 6 ft 8 in. You get the same size in inches, decimal feet and millimeters, plus the leaf area and a clean size string for your schedule. Treat the result as a nominal size, not a shop-drawing dimension.
Result
Planning estimate- Nominal size
- 3'0" x 6'8"
- Width (in)
- 36.00 in
- Height (in)
- 80.00 in
- Width (ft)
- 3.000 ft
- Height (ft)
- 6.667 ft
- Width (mm)
- 914.4 mm
- Height (mm)
- 2,032.0 mm
- Leaf area
- 20.00 sq ft
Width x height, as entered.
Nominal width x height. The actual leaf is usually a little smaller.
How it is calculated
- 1 Total inches = feet x 12 + inches, worked out separately for width and height.
- 2 Decimal feet = total inches / 12.
- 3 Millimeters = total inches x 25.4, since one inch is defined as exactly 25.4 mm.
- 4 Leaf area in sq ft = width in inches x height in inches / 144.
Assumptions to confirm
- Nominal size
- The size you enter is treated as the nominal door size. The actual door leaf is often slightly smaller than nominal, and the frame rough opening is typically larger than the leaf. Confirm the real dimensions with the door and frame manufacturer.
- Leaf area
- Leaf area is just nominal width x height. It ignores any undercut, lite cutouts, or the difference between nominal and actual size.
- Inches over 12
- You can enter more than 12 in. For example 0 ft 84 in is written back as 7 ft 0 in.
- Millimeter rounding
- Millimeters are shown to one decimal place. Metric door sizes from a manufacturer are usually a rounded module, so compare against their table rather than this conversion.
This is an early planning estimate, not a quotation. Check quantities against your drawings, your specification and the manufacturer's data.
Questions about this calculator
What does a door size like 3068 mean?
It is common shorthand for 3 ft 0 in wide by 6 ft 8 in tall. The first two digits are feet and inches of width, the last two are feet and inches of height.
Is the rough opening the same as the door size?
No. The rough opening is typically larger than the door leaf to leave room for the frame and shims. The exact allowance depends on the frame type, so check the frame manufacturer.
How many millimeters is an inch?
Exactly 25.4 mm. A 36 in door is 914.4 mm.
Related tools
Take these numbers off the drawings
Estimateria reads the door, hardware and finish schedules out of your PDFs into a priced grid, so the quantities you check here start from the set instead of a retype.