This converter turns feet into millimeters instantly, using the exact factor 1 foot = 304.8 millimeters. Type any number and the result updates as you go — nothing is sent to a server, so the arithmetic happens entirely in your browser.
Twelve inches, or exactly 0.3048 metres — still standard for human height and aviation altitude in the US. One thousandth of a metre — the finest gradation on a standard ruler.
Because the relationship is a simple proportion, one multiplication does the whole job. The table further down gives pre-computed values for the amounts people look up most often, and the result panel also reports the reverse conversion so you can check the figure both ways.
The formula
feet- The amount you are converting, measured in feet
304.8- The exact number of millimeters in one foot
millimeters- The converted result
How it works, step by step
- Enter the number of feet you want to convert.
- The value is multiplied by 304.8, the exact conversion factor.
- The result is displayed in millimeters, rounded for readability.
- The unrounded value and the reverse conversion appear underneath so you can verify it.
Worked examples
Converting 5 feet
Multiply 5 by 304.8. That gives 1,524 millimeters. A quick sanity check: one foot is larger than one millimeter, so the number should get bigger — and it does.
Converting 72 feet
72 × 304.8 = 21,945.6 millimeters. Working backwards, 21,945.6 ÷ 304.8 returns 72 feet, which confirms the factor is applied the right way round.
How to read your score
Frequently asked questions
How many millimeters are in one foot?
Exactly 304.8. Every conversion on this page is that single number multiplied by your input, so the result carries no rounding error beyond what is shown.
What is the formula to convert feet to millimeters?
Millimeters = feet × 304.8. To reverse it, divide instead: feet = millimeters ÷ 304.8, which is the same as multiplying by 0.003280839895.
Is the foot bigger than the millimeter?
Yes. One foot equals 304.8 millimeters, so it is the larger unit.
Why does my answer differ slightly from other feet to mm converters?
Most differences come from rounding the factor too early. This tool keeps full double precision through the calculation and only rounds at the final display step, and it also shows the unrounded value so you can see exactly where any difference appears.
What is a foot?
Twelve inches, or exactly 0.3048 metres — still standard for human height and aviation altitude in the US.
What is a millimeter?
One thousandth of a metre — the finest gradation on a standard ruler.
Feet to millimeters reference table
| Feet | Millimeters |
|---|---|
| 0.5 ft | 152.4 mm |
| 1 ft | 304.8 mm |
| 2 ft | 609.6 mm |
| 3 ft | 914.4 mm |
| 5 ft | 1,524 mm |
| 10 ft | 3,048 mm |
| 15 ft | 4,572 mm |
| 20 ft | 6,096 mm |
| 25 ft | 7,620 mm |
| 50 ft | 15,240 mm |
| 75 ft | 22,860 mm |
| 100 ft | 30,480 mm |
| 250 ft | 76,200 mm |
| 500 ft | 152,400 mm |
| 1000 ft | 304,800 mm |
Exact factor: 1 foot = 304.8 millimeters. Values rounded for display.