Square Centimeters to Square Miles (cm² to mi²)

1 square centimeter equals 3.861021585×10⁻¹¹ square miles (rounded).

1 square centimeter = 3.861021585×10⁻¹¹ square miles

How to convert square centimeters to square miles

To convert square centimeters to square miles, multiply the number of square centimeters by 3.861021585×10⁻¹¹. The factor is rounded to 10 significant digits. To go the other way, multiply square miles by 25,899,881,103 (rounded).

square miles = square centimeters × 3.861021585×10⁻¹¹

Example: 10 square centimeters = 3.861021585×10⁻¹⁰ square miles.

About these units

Square Centimeter (cm²)

Metric (SI)Current unit

A square one centimeter on a side; 1/10,000 of a square meter.

Physicists, rather than surveyors, put the centimeter at the center of a measuring system. Carl Friedrich Gauss proposed absolute units based on length, mass and time in 1832, choosing the millimeter, and in 1873 a British Association committee including James Clerk Maxwell and William Thomson (Lord Kelvin) recommended the centimeter, gram and second instead. In that CGS system the square centimeter turns up inside derived units, such as the stokes of kinematic viscosity, defined as one square centimeter per second.

A square centimeter is one ten-thousandth of a square meter, so 10,000 of them fill a square meter. It is a natural size for small flat things: a square inch is exactly 6.4516 cm², and a square foot is exactly 929.0304 cm². Because the CGS system defined force and pressure with the centimeter, the dyne per square centimeter became its unit of pressure, called the barye, which equals 0.1 pascal. SI practice prefers the square meter for large areas and the square millimeter for very small ones.

1 square centimeter = 0.0001 square meters (exactly).

Sources: Wikipedia: Centimetre-gram-second system of units; Wikipedia: Square centimetre; NIST Guide to the SI, Appendix B.8: conversion factors

Square Mile (mi²)

US & ImperialCurrent unit

640 acres or about 2.59 km². Used for the area of cities, states and countries in the US and UK.

A thousand Roman paces, mille passus, became the mile, and under Elizabeth I Parliament fixed the statute mile at eight furlongs, or 5,280 feet, in place of the older Roman-based value. The square mile inherits that length. Its most famous use came in the United States: the Land Ordinance of 1785 started the Public Land Survey System so that western land could be surveyed and sold to pay war debts, beginning with the Seven Ranges in eastern Ohio.

In that system a section is roughly one square mile, or 640 acres, and a township is 36 sections in a square six miles on a side. One square mile is nearly 2.59 million square meters. Chicago's Midway International Airport, at about 650 acres, covers roughly 1.02 square miles. Beware the phrase mile square: a region 20 miles square has 400 square miles, but so does a rectangle 10 by 40 miles. The US survey version of the mile was retired from 1 January 2023, but the international square mile remains the unit for cities, states and countries in the US and UK.

1 square mile = 2,589,988.11 square meters (approximately).

Sources: Wikipedia: Square mile; Wikipedia: Public Land Survey System; Wikipedia: Mile

Related conversions

See all area units.