Calculators

Unit Converter

Convert length, weight and temperature between metric and imperial units.

What are you converting?What are you converting?
cm
Result70.866142 in180 cm

How it works

Length and weight convert by routing through a base unit — every length is expressed in metres first, every weight in grams — which means one table of factors handles every possible pair. Temperature cannot work that way, because its scales have different zero points as well as different step sizes, so it is converted through Celsius with an offset as well as a ratio.

result = value × (factor of source unit) ÷ (factor of target unit)
value
The number you entered
factor
How many base units one of that unit represents
base unit
Metre for length, gram for weight, Celsius for temperature
°F = °C × 9/5 + 32
The temperature conversion, with its offset

Worked example

Converting 6 feet into centimetres.

  1. 1One foot is 0.3048 metres, so 6 × 0.3048 = 1.8288 metres
  2. 2One centimetre is 0.01 metres
  3. 3Divide: 1.8288 ÷ 0.01 = 182.88

6 feet is 182.88 cm.

Frequently asked questions

Why is temperature handled differently from length and weight?

Length and weight scales share a zero — zero metres and zero feet are the same nothing — so a single multiplication converts between them. Temperature scales do not: 0 °C and 0 °F are different temperatures. Converting therefore needs both a ratio and an offset, which is why you cannot simply multiply Celsius by a factor to get Fahrenheit.

Is there a temperature where Celsius and Fahrenheit agree?

Yes, at −40. It is the one point where the two scales cross, which makes −40 °C and −40 °F the same temperature. It is also a useful sanity check on any conversion you write yourself.

How exact are these conversions?

The imperial factors used here are the internationally agreed exact definitions — an inch is exactly 25.4 mm and a pound is exactly 0.45359237 kg — so the only imprecision comes from rounding the displayed result. Conversions are not approximations; the rounding is.

What is the difference between weight and mass?

Strictly, kilograms measure mass and the newton measures weight, which is the force gravity exerts on that mass. In everyday use the two are treated as interchangeable because gravity is effectively constant across the Earth's surface. This converter works in mass, which is what a kitchen or bathroom scale reports.

Why does a US pint differ from a UK pint?

The two systems diverged historically and were never reconciled — a US pint is about 473 ml, a UK pint about 568 ml. The same applies to gallons and fluid ounces, which is why recipes crossing the Atlantic often go wrong. Length and weight units, covered here, are the same in both systems.

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