Unit Conversion
Unit Converter
Convert length, weight, temperature, area, volume and speed: inches, feet, miles, pounds, °F, gallons, acres.
Updated:
Result
Updates as you type1 in =
2.54 cm
- Millimetre
- 25.4 mm
- Metre
- 0.0254 m
- Kilometre
- 0.0000254 km
- Foot
- 0.08333333 ft
- Yard
- 0.02777778 yd
- Mile
- 0.0000157828 mi
- Nautical mile
- 0.0000137149 nmi
How it's calculated
Each unit is tied to its group's base SI unit (metre, kilogram, square metre, litre, metre per second) by an exact factor. The value is turned into the base unit and then into the target unit. Inches, feet, miles and pounds are exact under the 1959 international agreement, and both gallons are exact by definition; results show about seven significant figures. Temperature uses a formula, because the scales start at different zero points.
Worked example
- How tall is 5 ft 10 in? 70 × 2.54 = 177.8 cm
- 11 stone in kg: 11 × 6.35029318 = 69.85322 kg
- An oven at 350 °F: (350 − 32) / 1.8 = 176.6667 °C
Conversion tables
Common conversions
| Quantity | Unit | Equals |
|---|---|---|
| Quantity: Length | Unit1 in | Equals2.54 cm |
| Quantity: Length | Unit1 ft | Equals0.3048 m |
| Quantity: Length | Unit1 yd | Equals0.9144 m |
| Quantity: Length | Unit1 mi | Equals1.609344 km |
| Quantity: Length | Unit1 nmi | Equals1.852 km |
| Quantity: Weight | Unit1 lb | Equals0.4535924 kg |
| Quantity: Weight | Unit1 kg | Equals2.204623 lb |
| Quantity: Weight | Unit1 oz | Equals28.34952 g |
| Quantity: Weight | Unit1 st | Equals6.350293 kg |
| Quantity: Area | Unit1 acres | Equals4,046.856 m² |
| Quantity: Area | Unit1 ha | Equals2.471054 acres |
| Quantity: Area | Unit1 sq ft | Equals0.09290304 m² |
| Quantity: Volume | Unit1 US gal | Equals3.785412 L |
| Quantity: Volume | Unit1 UK gal | Equals4.54609 L |
| Quantity: Volume | Unit1 US cups | Equals236.5882 ml |
| Quantity: Volume | Unit1 UK pt | Equals568.2613 ml |
| Quantity: Speed | Unit1 mph | Equals1.609344 km/h |
| Quantity: Speed | Unit1 kn | Equals1.852 km/h |
| Quantity: Speed | Unit1 m/s | Equals3.6 km/h |
Celsius and Fahrenheit
| °C | °F | K |
|---|---|---|
| °C: -40 | °F-40 | K233.15 |
| °C: -20 | °F-4 | K253.15 |
| °C: 0 | °F32 | K273.15 |
| °C: 10 | °F50 | K283.15 |
| °C: 20 | °F68 | K293.15 |
| °C: 25 | °F77 | K298.15 |
| °C: 30 | °F86 | K303.15 |
| °C: 37 | °F98.6 | K310.15 |
| °C: 40 | °F104 | K313.15 |
| °C: 100 | °F212 | K373.15 |
Frequently asked questions
How many centimetres are in an inch?
Exactly 2.54 cm, fixed by the 1959 international yard and pound agreement. A foot (12 inches) is 30.48 cm and a yard is 0.9144 m.
How many kilometres are in a mile?
A mile is exactly 1.609344 km, so 100 km/h is about 62.14 mph. A nautical mile, used at sea and in the air, is 1,852 m.
How do you convert Fahrenheit to Celsius?
°C = (°F − 32) / 1.8 and °F = °C × 1.8 + 32. So 100 °F is 37.77778 °C and a body temperature of 37 °C is 98.6 °F. Kelvin is °C + 273.15.
How many kilograms are in a pound and in a stone?
A pound is exactly 0.45359237 kg (about 0.45); a stone is 14 pounds, 6.350293 kg. An ounce is a sixteenth of a pound, 28.34952 g.
Is a UK gallon the same as a US gallon?
No. A UK (imperial) gallon is 4.54609 litres, a US gallon 3.785412 litres: the imperial gallon is about 20% larger. UK and US pints and fluid ounces differ too, which matters in recipes and fuel economy figures.
How big is an acre?
An acre is 43,560 square feet, 4,046.856 m² or 0.4046856 hectares. A hectare (10,000 m²) is about 2.47 acres.
Sources
Results are for guidance only. Check with the relevant authority or a qualified professional before relying on them.