Metric conversion chart
The metric system runs on powers of ten, so converting between units means moving a decimal point. This chart covers length, mass, and volume within the metric system, plus the everyday conversions to US and imperial units.
Metric length
| Unit | Equivalent |
|---|---|
| 1 kilometre (km) | 1,000 metres |
| 1 metre (m) | 100 centimetres |
| 1 centimetre (cm) | 10 millimetres |
| 1 metre (m) | 1,000 millimetres |
| 1 millimetre (mm) | 1,000 micrometres |
Metric mass
| Unit | Equivalent |
|---|---|
| 1 tonne (t) | 1,000 kilograms |
| 1 kilogram (kg) | 1,000 grams |
| 1 gram (g) | 1,000 milligrams |
| 1 milligram (mg) | 1,000 micrograms |
Metric volume
| Unit | Equivalent |
|---|---|
| 1 litre (L) | 1,000 millilitres |
| 1 millilitre (mL) | 1 cubic centimetre |
| 1 cubic metre (m³) | 1,000 litres |
| 1 litre (L) | 1,000 cubic centimetres |
Metric to US / imperial
| Metric | Approx. equivalent |
|---|---|
| 1 metre | 3.281 feet (39.37 in) |
| 1 kilometre | 0.621 miles |
| 1 centimetre | 0.394 inches |
| 1 kilogram | 2.205 pounds |
| 1 gram | 0.0353 ounces |
| 1 litre | 0.264 US gallons (1.057 qt) |
| 1 millilitre | 0.0338 fluid ounces |
Within the metric system, each step up or down is a factor of ten, so a kilometre is a thousand metres and a centimetre is a hundredth of a metre. To convert, count the powers of ten between units and shift the decimal that many places. The prefixes kilo, centi, and milli mean a thousand, a hundredth, and a thousandth.
Need notation or other conversions?
See the Scientific Notation Chart, or use the unit conversion calculators for exact figures.
Why metric conversion is easy
Every metric unit is related to the next by a power of ten, which mirrors how our number system works. Moving from metres to centimetres multiplies by 100, the same as shifting the decimal two places to the right. There are no awkward factors like twelve inches to a foot or sixteen ounces to a pound, so converting is just counting zeros.
Metric to imperial
Converting to US or imperial units needs fixed factors rather than powers of ten. A metre is about 3.28 feet, a kilogram about 2.2 pounds, and a litre about 0.26 US gallons. These are approximate; for precise work use the full conversion factors, since a metre is defined as exactly 39.3701 inches.
FAQ
How many centimetres are in a metre?
One hundred. The prefix centi means one hundredth, so a centimetre is a hundredth of a metre and a metre holds 100 of them.
How do I convert kilometres to miles?
Multiply kilometres by about 0.621. So 10 km is roughly 6.21 miles.
Is a millilitre the same as a cubic centimetre?
Yes. One millilitre equals exactly one cubic centimetre, which is why engine and medical volumes are quoted in cc or mL interchangeably.