Convert feet to millimeters instantly. Enter a value below, or use the formula and reference table further down the page.
In practice
Feet to millimetres is a conversion used in engineering, architecture drawings and imported equipment, where the US quotes feet and the rest of the world works in millimetres. One foot is exactly 304.8 mm, so a 10 ft ceiling is 3,048 mm and an 8 ft ceiling is 2,438.4 mm — close to the 2,400 mm standard ceiling height in many countries, but not identical. That small gap is why imported cabinets, doors and appliances can look right on paper and still need a few millimetres of packing or trimming when fitted.
How to convert feet to millimeters
Multiply the value by 304.8.
mm = ft × 304.8Example: 10 ft = 3048 mm.
Feet to Millimeters conversion table
| Feet (ft) | Millimeters (mm) |
|---|---|
| 1 ft | 304.8 mm |
| 2 ft | 609.6 mm |
| 3 ft | 914.4 mm |
| 4 ft | 1219.2 mm |
| 5 ft | 1524 mm |
| 10 ft | 3048 mm |
| 15 ft | 4572 mm |
| 20 ft | 6096 mm |
| 25 ft | 7620 mm |
| 50 ft | 15240 mm |
| 100 ft | 30480 mm |
Frequently asked questions
How many millimeters is 1 foot?
1 foot equals 304.8 millimeters.
What is the formula to convert ft to mm?
To convert ft to mm, multiply the value by 304.8. The full formula is: mm = ft × 304.8.
How do I convert millimeters back to feet?
Use the same calculator above and type your value into the millimeters field instead — it converts in both directions. Or use the reverse formula: ft = mm ÷ 304.8.
Is the ft to mm conversion exact?
The conversion factor used here (304.8) is the standard internationally defined value. Results on this page are rounded to four decimal places for readability.