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Feet to millimeters converter

Read a quantity in ft, then express the same length in mm. The units are defined below to avoid mixing similarly named standards.

≈ 304.8 mm

Up to 12 significant digits are displayed; floating-point results are approximate. No value is saved.

Direct example

1 ft ≈ 304.8 mm.

Formula and calculation

mm = ft × 304.8

Substituting 1 ft gives approximately 304.8 mm. Definitions use the constants above; arithmetic uses browser floating point and displays at most 12 significant digits. The rounded table is not an instrument calibration or certified measurement.

Which units does this page use?

feet: international foot: 0.3048 metres, not the obsolete US survey foot.

millimeters: one thousandth of a metre.

When this direction is useful

Start here when your source record uses ft for property specifications and height measurements, but the receiving specification is expressed in mm for small components and manufacturing dimensions. Enter the original quantity rather than reusing a previously rounded result. If your source uses mm, use the reverse converter instead.

Conversion table

Approximate displayed values, with the same definitions as the converter
feet (ft)millimeters (mm)
00
1304.8
51524
103048
10030480

Limits and interpretation

These are non-negative physical quantities; negative inputs are rejected. Converting a unit changes neither the measured object nor the original precision. Use a decimal dot; grouping commas are not accepted. No external rates, live data or account are involved.

Frequently asked questions

Can I convert the other way?

Yes. Convert millimeters to feet with the inverse equation. Rounding a result before converting it back can introduce a small difference.

Are these the same as every similarly named unit?

No. Check the two definitions above. International length, avoirdupois mass, US customary liquid measures and temperature readings are explicitly distinguished; an ambiguous label on a source document must be resolved first.

Where do the conversion definitions come from?

They use SI and defined customary conversion relationships. See the NIST Guide for the Use of SI. Output formatting is this tool's display policy, not extra measurement accuracy.

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