Length and Area
fttomm
Convert feet (ft) to millimetres (mm).
Factor1 ft = 304.8 mm
Converter
ft
Accepts numbers or expressions, e.g. 150 + 14.7
Result
mm
Rendered to 6 significant figures.
Formula
Formula
mm = ft × 304.8
Multiply any value in feet by 304.8 to obtain the value in millimetres.
Worked example
Convert 1 ft to mm.
- 01Start with 1 ft.
- 02Multiply by the conversion factor: 1 × 304.8 = 304.8 mm.
Result1 ft = 304.8 mm
Conversion table
| ft | mm |
|---|---|
| 1 | 304.8 |
| 2 | 609.6 |
| 5 | 1524 |
| 10 | 3048 |
| 20 | 6096 |
| 50 | 15240 |
| 100 | 30480 |
| 200 | 60960 |
| 500 | 1.5240e+5 |
| 1000 | 3.0480e+5 |
Reference values rounded to 5 significant figures for display.
FAQ
What is the conversion factor from ft to mm?
1 ft equals 304.8 mm. To convert, multiply the value in feet by 304.8.
How do I convert 1 ft to mm?
1 ft = 304.8 mm. For any value, multiply by 304.8.
How do I convert mm back to ft?
Divide by the same factor — or equivalently, multiply by 0.00328084. So 1 mm = 0.00328084 ft.
When would I need to convert foot to millimetre?
Length conversions appear in piping, layout, and mechanical drawings — particularly when reconciling imperial fittings or instrument lengths with metric plant drawings.
Is the conversion exact?
Yes. Both ft and mm are defined by exact SI relationships, so the displayed factor is exact (any rounding shown is only for display).