About the ft to mm calculation
One foot is exactly 304.8 millimeters, so converting between them is a single multiplication. Enter any value above and the result updates as you type. Used for human height in the US and UK, and for altitude in aviation globally. The standard fine unit on engineering drawings and rainfall figures.
Formula
mm = ft × 304.8
1 ft = 304.8 mm
1 mm = 0.00328084 ftWorked example
To convert 6 ft, multiply by 304.8: 6 × 304.8 = 1,828.8 mm.
Frequently asked questions
How many millimeters are in a foot?
There are 304.8 millimeters in one foot. To convert any amount, multiply the number of feet by 304.8.
How do I convert millimeters back to feet?
Divide instead of multiplying, or equivalently multiply by 0.00328084. One millimeter is 0.00328084 feet.
Is this conversion exact?
Yes. Since the international agreement of 1959, the relationship between feet and millimeters is defined exactly rather than measured, so the only rounding here is in how many decimal places we show.
Where is each of these units used?
Feet: used for human height in the US and UK, and for altitude in aviation globally. Millimeters: the standard fine unit on engineering drawings and rainfall figures.
Sources
- NIST Special Publication 811 — Guide for the Use of the International System of Units