Foot to Millimetre Converter
Convert feet to mm instantly. Free feet to mm calculator with formula, examples and FAQs.
Quick answer
1 feet equals 304.8 mm. To convert feet to mm, multiply the feet value by 304.8 — so 10 feet = 3048 mm. This factor is exact, and the reverse conversion (mm to feet) simply divides by 304.8 instead of multiplying.
Converted value
304.80
1.00 feet = 304.80 mm
What is feet to mm?
Going from feet to mm keeps the underlying length the same — only the unit changes. Because feet is the unit US users, pilots and anyone filling metric forms tend to start with, this direction is especially useful. Apply mm = feet × 304.8 and the result is precise every time.
Real-world uses: why convert feet to mm?
Converting feet to mm bridges two ways of measuring the same thing. People do it most often when understanding height in metric for forms and IDs, and on the receiving side when matching print bleed and design specs. Having the exact value — not a rough estimate — prevents costly mistakes in paperwork, purchases and planning.
- •Converting US property and ceiling heights to metric.
- •Reading aviation altitude given in feet.
- •Checking furniture and appliance clearances.
- •Understanding height in metric for forms and IDs.
- •Matching print bleed and design specs.
Who uses this conversion?
How the feet to mm conversion is calculated
This is the same arithmetic that calculators and search engines use — no rounded shortcuts.
mm = feet × 304.8
- Both feet and mm are defined in terms of the same base unit, the metre.
- 1 feet = 0.3048 metre, and 1 mm = 0.001 metre.
- Divide one definition by the other to get the conversion factor: 0.3048 ÷ 0.001 = 304.8.
- So mm = feet × 304.8. Multiply any feet value by 304.8 to get the result in mm.
Precision: The conversion factor is exact by international definition, so the result is an exact rational number. We display it rounded to four decimal places (or four significant figures for very small values).
Example calculations
- •1 feet = 304.8 mm
- •6 feet = 1828.8 mm
- •10 feet = 3048 mm
feet to mm quick reference table
Common feet values converted to mm, each calculated with the exact factor.
| feet | mm |
|---|---|
| 10 | 3048 |
| 25 | 7620 |
| 50 | 15240 |
| 100 | 30480 |
| 250 | 76200 |
| 500 | 152400 |
| 1000 | 304800 |
| 2500 | 762000 |
| 5000 | 1524000 |
| 10000 | 3048000 |
Common mistakes to avoid
- •Reading the result the wrong way round. Confirm the answer is in mm, not feet, before you rely on it.
- •Truncating instead of rounding, which compounds error across larger feet values.
- •Mixing metric and imperial units midway through a multi-step conversion instead of converting to a single base unit first.
Common questions about length conversions
Is this length conversion exact?
Yes. Factors such as 1 inch = 25.4 mm and 1 mile = 1,609.344 m are exact by international agreement, so the only rounding is in how many decimals we display.
Why do my results differ slightly from another tool?
Almost always because the other tool rounds the factor (e.g. 0.62 instead of 0.621371) or rounds partway through. We keep full precision and round only the final value.
Metric or imperial — which should I use?
Use metric (m, cm, km) for science and most countries, and imperial (ft, in, miles) for US and UK everyday distances. This page bridges the two exactly.
Can I round the answer?
Yes. For everyday use one or two decimals is plenty; engineering and science may need more. Round only at the end to avoid cumulative error.
History of these units
History of the foot
imperial / US customary
The foot has roots in the length of a human foot and varied widely before standardisation. The international foot is now exactly 0.3048 metres and stays common in US construction and aviation altitude.
History of the millimetre
metric
The millimetre is one-thousandth of a metre. As metric precision spread through engineering in the 19th and 20th centuries, it became the default unit for technical drawings and machined tolerances.
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Frequently asked questions
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