5 cm in inches, feet and meters

Eight units, one conversion

Select a source unit, type a number, and see the result in all 8 units at once: millimetres, centimetres, metres, kilometres, inches, feet, yards and miles. Every conversion is anchored to a single exact ratio: 1 inch = 2.54 cm, adopted internationally in 1959. No rounding in the math, only in the display.

Conversion reference table

All values are exact or rounded to 6 significant figures:

Unit	In cm	In inches	In feet	In km / miles
1 mm	0.1	0.03937	0.003281	-
1 cm	1	0.3937	0.03281	-
1 m	100	39.370	3.2808	0.001 km
1 km	100,000	39,370	3,280.8	0.62137 mi
1 inch	2.54	1	0.08333	-
1 foot	30.48	12	1	0.3048 m
1 yard	91.44	36	3	0.9144 m
1 mile	160,934	63,360	5,280	1.60934 km

Practical examples

Person's height: 5 feet 11 inches = 5 x 12 + 11 = 71 inches. 71 x 2.54 = 180.34 cm = 1.803 m. Most of the world uses centimetres for height; the US and UK use feet and inches.
Quick rule: multiply total inches by 2.54 to get centimetres

TV screen diagonal: 55 inches x 2.54 = 139.7 cm. A "55-inch" television has a screen diagonal of nearly 140 cm. The physical width is about 121 cm for a 16:9 panel.
Screen sizes are always the diagonal, never width or height

10K road race: 10 km x 0.62137 = 6.214 miles. A half marathon is 21.097 km = 13.109 miles. A full marathon is 42.195 km = 26.219 miles.
Quick rule: multiply km by 0.6 for a fast approximate mileage

Room dimensions: A 12 x 15 foot room = 3.658 x 4.572 metres = 16.72 m2. European floor plans use metres and square metres; US listings use feet and square feet (180 sq ft here).
Divide feet by 3.28 or multiply by 0.3048 for metres

Fabric or rope: 2.5 yards = 2.5 x 0.9144 = 2.286 metres. US craft patterns list requirements in yards; European fabric is sold by the metre. Buy 2.3 m for a 2.5-yard pattern.
1 yard is about 91.4 cm - slightly shorter than a metre

Quick mental math tricks

km to miles: multiply by 0.6. Example: 80 km x 0.6 = 48 miles (actual: 49.7).

miles to km: multiply by 1.6. Example: 30 miles x 1.6 = 48 km (actual: 48.28).

feet to metres: divide by 3 and subtract 10%. Example: 15 ft / 3 = 5, minus 10% = 4.5 m (actual: 4.572).

inches to cm: multiply by 2.5. Example: 10 in x 2.5 = 25 cm (actual: 25.4). Error is under 2%.

A brief history of length measurement

Ancient length units were body-based: the Egyptian cubit (forearm to fingertip, about 52 cm), the Roman foot (29.6 cm), the inch (thumb width), the yard (reportedly nose to outstretched thumb of King Henry I). These varied between kingdoms and caused constant confusion in trade.

The metric system came from the French Revolution (1790). Scientists defined the metre as one ten-millionth of the pole-to-equator distance. The British imperial system was formalized in 1824, building on older customs. The mile settled at 5,280 feet thanks to Queen Elizabeth I in 1593 (8 furlongs of 660 feet each - a furlong being the length of a ploughed furrow).

In 1959, six countries agreed that 1 yard = 0.9144 m exactly, making 1 inch = 2.54 cm exactly. This single ratio powers every conversion in this calculator. Today only the US, Liberia and Myanmar have not adopted metric as their primary system.

FAQ

What is the exact relationship between inches and centimetres?

Exactly 1 inch = 2.54 cm. This is not an approximation - it is exact by international definition (1959). All metric-imperial length conversions derive from this single anchor point.

Why are there 5,280 feet in a mile?

Queen Elizabeth I set the statute mile at 8 furlongs in 1593. A furlong was 660 feet (40 rods of 16.5 feet each). So 8 x 660 = 5,280. The furlong was the standard ploughed-furrow length in English agriculture.

Is a nautical mile the same as a regular mile?

No. A nautical mile is 1,852 m (1.852 km), defined as one arc-minute of latitude. A statute mile is 1,609.344 m. Nautical miles are used in aviation and maritime navigation. The speed unit "knot" is one nautical mile per hour.

How do I convert feet-and-inches to centimetres?

Convert everything to inches first, then multiply by 2.54. Example: 6 ft 2 in = (6 x 12) + 2 = 74 inches. 74 x 2.54 = 187.96 cm.

Which is longer, a yard or a metre?

A metre is about 9.4% longer. 1 yard = 0.9144 m. A 100-metre sprint is roughly 109.4 yards - about 10 yards longer than a 100-yard dash.

Are UK miles and US miles the same?

Yes, since 1959 both are exactly 1,609.344 metres. Before that, the US survey foot differed by about 2 parts per million - important for land surveying, irrelevant for daily use. The US retired the survey foot in 2022.

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5 cm - how many inches, feet and meters?

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