Length converter

Feet to millimeters.

Convert foot-based stock lengths into millimeter dimensions for a metric cutting list.

Feet (ft)Inch fraction precision

8 ft = 2,438.4 mm

Nearest inch fraction≈ 96 in

Fraction rounding difference-0 mm

Metric length2,438.4 mm

Feet and inches8 ft 0 in

The marker shows the fractional part of one inch. This diagram illustrates tick positions; it is not a physical-size ruler.

Reverse conversion ↔Measure on screen ↗

Conversion formula

millimeters = feet × 304.8

Enter the source length above. The result updates immediately. These calculations use exact length definitions: 1 m = 100 cm = 1000 mm, 1 in = 25.4 mm, and 1 ft = 12 in. Only the displayed answer and fractional ruler mark are rounded. The feet-and-inches output splits a length into whole feet and remaining inches; decimal feet do not encode an inch count.

Worked example

8 ft is exactly 2438.4 mm. Cutting that length down to 2400 mm leaves a nominal 38.4 mm difference, but the usable offcut depends on the saw kerf and trimming. A five-and-a-half-foot length is 5.5 ft and converts to 1676.4 mm.

Conversion table: ft → mm

Select a source value to load it into the calculator. Decimal results are displayed to at most six places; inch fractions in this table are rounded to 1/16 inch.

Feet → Millimeters
Feet (ft)	Millimeters (mm)	Nearest inch fraction
	152.4	≈ 6 in
	304.8	≈ 12 in
	609.6	≈ 24 in
	762	≈ 30 in
	914.4	≈ 36 in
	1,219.2	≈ 48 in
	1,828.8	≈ 72 in
	2,438.4	≈ 96 in
	3,048	≈ 120 in
	3,657.6	≈ 144 in

When to use this conversion

Use this for board lengths, purchased tubing, furniture plans, and measurements that need to be communicated in millimeters. Decimal feet are not a notation for feet and inches. Enter 2.5 for 2 ft 6 in, not 2.6. Check the separated feet-and-inches output before copying the metric result.

The result may contain a decimal millimeter even when the input is a whole foot. Do not remove it silently. Whether you may round to a whole millimeter depends on the required fit and how accurately the original length was measured.

Exact conversion versus a ruler reading

The unit relationship is exact, but a measured object may have uncertainty. At 1/16 inch, the maximum rounding difference is half a tick: 1/32 inch, or 0.79375 mm. The calculator shows the actual rounding difference for your value. Use a finer division only if the source measurement and physical instrument support that precision.

Next steps

Numerical conversion needs no display calibration. Comparing a physical object against your screen does. Use the ruler for small objects, a verified paper ruler away from your display, or an appropriate calibrated instrument for safety-critical measurements.

Measure on screen Printable ruler PDFs Screen calibration guide How to read a ruler

Related converters

Millimeters to feet.Translate a millimeter drawing dimension into a foot-based length without changing the underlying measurement.Inches to millimeters.Convert a decimal, fraction, or mixed inch measurement into millimeters. No need to turn 2 3/8 into a decimal first.Centimeters to millimeters.Move between centimeter readings and millimeter dimensions without losing the decimal part.Meters to millimeters.Convert a larger metric length into the fine units used on a cutting list or engineering drawing.Feet to centimeters.Convert a decimal-foot length to centimeters and verify how the fractional foot relates to inches.

Length converters ↗

Reference: NIST unit conversion factors. Calculations use the international foot, not historical survey-foot units. Fractions are explicitly approximate. NIST ↗