Square Millimeters to Square Feet (mm² to ft²)

1 square millimeter equals 0.00001076391042 square feet (rounded).

1 square millimeter = 0.00001076391042 square feet

How to convert square millimeters to square feet

To convert square millimeters to square feet, multiply the number of square millimeters by 0.00001076391042. The factor is rounded to 10 significant digits. To go the other way, multiply square feet by 92,903.04.

square feet = square millimeters × 0.00001076391042

Example: 10 square millimeters = 0.0001076391042 square feet.

About these units

Square Millimeter (mm²)

Metric (SI)Current unit

A square one millimeter on a side. Used for the cross-section of wires and small parts.

Gauss gets the credit for putting the millimeter at the base of a scientific measuring system. His 1832 proposal for absolute units used the millimeter, milligram and second, although the centimeter-based CGS system later won out among scientists. The square millimeter is a one-thousandth-by-one-thousandth square of a meter, so it takes a million of them to make a square meter, and it has no famous inventor of its own.

Electricians know it best. Wire and cable sizes are given as the cross-sectional area of the copper conductor, and the standard sizes listed for UK domestic wiring are 1, 1.5, 2.5, 4, 6 and 10 mm². Twin and earth cable of 2.5 mm² typically serves sockets on a 16 A radial or 32 A ring circuit, 1 mm² serves lighting on a 6 A breaker, and 4 mm² feeds a cooker or shower. Conductor size depends on current capacity and allowed voltage drop, not on voltage alone. One square inch is exactly 645.16 mm², so small parts in either system compare easily.

1 square millimeter = 0.000001 square meters (exactly).

Sources: Wikipedia: Electrical wiring in the United Kingdom; Wikipedia: Centimetre-gram-second system of units; Wikipedia: Square metre

Square Foot (ft²)

US & ImperialCurrent unit

Exactly 0.09290304 m². The standard unit for floor areas and real estate in the US, UK and India.

Feet came first, and they were not all the same length. As a body-based unit, the foot ranged historically between about 250 and 335 millimeters, with ancient Greek and Roman feet near 300 mm. In medieval England a statute foot was set at 10/11 of an older Belgic foot, and Charlemagne's attempt around 790 to standardize units largely failed. The square foot is simply that length squared, so its size changed along with the foot.

The 1959 international agreement fixed the foot at exactly 0.3048 meter, so one square foot is exactly 0.09290304 m², or 144 square inches. The United Kingdom adopted the new foot in 1964. Today the square foot is the usual way of listing property in the United States, Canada, the United Kingdom, India, Pakistan, Singapore and Hong Kong, although the measuring convention varies: agents may measure corner to corner, subtract unheated space, or add heated space that extends beyond the end-to-end measurement. The world's smallest park has been reported at 2.6 sq ft.

1 square foot = 0.09290304 square meters (exactly).

Sources: Wikipedia: Square foot; Wikipedia: Foot (unit); NIST Guide to the SI, Appendix B.8: conversion factors

Related conversions

See all area units.