How many kilometres are in a mile?

One mile is exactly 1.609344 kilometres. A quick mental shortcut: multiply miles by 1.6 to get kilometres, or multiply kilometres by 0.6 to get miles.

How many mL is a US cup?

A US cup is about 237 mL, but an Australian metric cup is 250 mL. Australian tablespoons are also bigger: 20 mL versus the US 15 mL — worth checking when following overseas recipes.

How do I convert MPG to L/100km?

Divide 235.215 by the MPG figure. For example, 30 MPG (US) equals about 7.8 L/100km. Note that with L/100km, lower numbers are better, while with MPG higher is better.

Metric ⇄ Imperial Converter

Convert length, weight, temperature, cooking measures, fuel economy and speed between metric and imperial — instantly, in both directions.

Value From

Result To

Common conversions at a glance

Imperial → Metric	Metric → Imperial
1 inch = 2.54 cm	1 cm = 0.394 in
1 foot = 30.48 cm	1 metre = 3.281 ft
1 mile = 1.609 km	1 km = 0.621 miles
1 pound = 453.6 g	1 kg = 2.205 lb
1 ounce = 28.35 g	100 g = 3.53 oz
1 US gallon = 3.785 L	1 litre = 0.264 US gal
1 US cup = 237 mL	1 AU cup = 250 mL
70°F = 21.1°C	25°C = 77°F
30 MPG (US) ≈ 7.8 L/100km	8 L/100km ≈ 29.4 MPG (US)

US and Australian units aren't quite the same

Australia went metric in the 1970s, the United States never did — and anyone cooking from an American recipe in Melbourne (or reading an Australian road sign in miles-per-hour headspace) hits the differences fast:

Cups: a US cup is ~237 mL; an Australian metric cup is 250 mL. Close enough for soup, risky for baking.
Tablespoons: Australia's tablespoon is 20 mL (4 teaspoons); the US tablespoon is 15 mL (3 teaspoons). This one genuinely ruins recipes.
Gallons: a US gallon (3.785 L) is smaller than the old imperial gallon (4.546 L) still remembered by older Australians.
Fuel economy: the US uses miles per gallon where higher is better; Australia uses litres per 100 km where lower is better. The two are inversely related — divide 235.215 by one to get the other.
Body weight: Americans use pounds, Australians use kilograms (and sometimes stone, inherited from the UK: 1 stone = 14 lb = 6.35 kg).

Popular conversions

Each of these has its own page with a full conversion table and the exact formula:

kg → lblb → kgkm → mimi → kmcm → inin → cmft → mm → ft°C → °F°F → °CmL → cupscups → mLoz → gg → ozst → kgkg → stac → haha → acMPG → L/100kmL/100km → MPG

Quick mental shortcuts

km → miles: multiply by 0.6 (100 km/h ≈ 60 mph).
kg → lb: double it, then add 10% (80 kg → 160 + 16 ≈ 176 lb).
°C → °F: double it and add 30 for a rough answer (20°C → ~70°F). Exact: ×1.8 + 32.
cm → inches: divide by 2.5.

Frequently asked questions

How many kilometres in a mile?

Exactly 1.609344 km. Multiply miles by 1.6 for kilometres, or km by 0.6 for miles.

How do I convert Celsius to Fahrenheit?

Multiply by 1.8 and add 32. So 25°C = 77°F. In reverse: subtract 32, divide by 1.8.

Why do US and Australian cup measurements differ?

The US cup is defined from the US customary system (~237 mL), while Australia standardised on a metric 250 mL cup. Australian tablespoons are 20 mL versus the US 15 mL too.

How accurate are the conversions?

All factors are exact legal definitions (e.g. 1 inch = 25.4 mm) or standard reference values, computed to full precision and displayed to a sensible number of digits.