Centimeter to Foot

A centimeter (cm) is one hundredth of a meter (10⁻² m). It is the most familiar metric unit for body and clothing measurements — height, waist size, and shoe dimensions are typically expressed in centimeters in metric countries.

One foot equals exactly 30.48 centimeters. Equivalently, 1 centimeter is approximately 0.3937 inches. Since many people know both their height in feet and in centimeters, this conversion is one of the most frequently searched.

Exactly 100 centimeters equal one meter. The prefix centi- means one hundredth in the SI system, so this relationship is definitional rather than a conversion to memorize.

Centimeters are used for body measurements because human-scale dimensions work naturally as whole or simple decimal numbers — "175 cm" is easier to say than "1750 mm". Engineering switches to millimeters because precision matters more than readability: a 10.5 mm bolt is clearer than a 1.05 cm bolt when tenths of a millimeter are significant. The choice reflects the granularity needed in each context.

European clothing sizes are loosely based on body measurements in centimeters — a size 40 shirt often corresponds to a 40 cm collar, and dress sizes track waist measurements. US sizes use an arbitrary numbering system rooted in 19th-century convention, not direct metric measurements. This divergence was never internationally standardized, which is why a US size 8 dress does not directly correspond to a European 38, even though both systems derive loosely from body dimensions.

A foot is exactly 12 inches or 0.3048 meters — about the length of a standard 30 cm ruler. An average adult male foot is close to, but not exactly, one foot (typically 10–11 inches).

Exactly 5,280 feet equal one mile. There are 3 feet in a yard, 6 feet in a fathom, and 660 feet in a furlong. The 5,280 number originates from 8 furlongs of 660 feet — a historical land measurement system.

A "2×4" starts as a rough-sawn board measuring 2 inches by 4 inches. After kiln-drying and planing smooth, it shrinks to 1.5 × 3.5 inches. The lumber industry kept the nominal (pre-planing) names because sawmills had used them for over a century. A 2×6 is really 1.5 × 5.5 inches, a 2×8 is 1.5 × 7.25 inches, and so on. The convention frustrates DIYers but is so deeply embedded in building codes and construction practice that changing it would require rewriting thousands of structural engineering tables.

The US retained imperial units after independence from Britain, and feet-and-inches became culturally entrenched in medical records, sports statistics, and everyday conversation. Metric countries typically express height as a single centimeter number — "175 cm" — which is simpler than "5 feet 9 inches." The US has no legal requirement to switch, so the convention remains unchanged.

The international foot (used everywhere) is exactly 0.3048 meters. The US survey foot is slightly different: exactly 1200/3937 meters ≈ 0.30480061 meters. The difference is about 2 parts per million — negligible for most purposes, but detectable over long surveying distances. The US survey foot was officially retired in 2023; the international foot is now the US legal standard for all purposes.