Metric Unit Conversion
Practise converting metric units of length, mass and volume — all built on the easy power-of-ten system.
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How metric conversion works
The metric system is built on tens, which makes converting a matter of multiplying or dividing by 10, 100 or 1000. The prefixes tell you the size: kilo = 1000, centi = a hundredth, milli = a thousandth.
- Going to a smaller unit (m → cm), multiply.
- Going to a larger unit (g → kg), divide.
- Know the key links: 1 km = 1000 m, 1 m = 100 cm, 1 cm = 10 mm, 1 kg = 1000 g, 1 L = 1000 mL.
Worked examples
Tips & common mistakes
Because everything moves by powers of ten, converting is really just shifting the decimal point — the same place-value idea as multiplying by 10 or 100. Learn the prefixes once and they apply to length, mass and volume alike. Type the number.
- Multiplying when you should divide — smaller unit means a bigger number.
- Using the wrong factor (1 km is 1000 m, not 100).
- Mixing up centi (hundredth) and milli (thousandth).
Frequently asked questions
How do you convert metric units?
Multiply when moving to a smaller unit and divide when moving to a larger one, using the power-of-ten factor between them.
What do kilo, centi and milli mean?
Kilo means 1000, centi means one hundredth, and milli means one thousandth. So a kilometre is 1000 metres and a millimetre is a thousandth of a metre.
Why is the metric system easy to convert?
Because every step is a power of ten, so converting is just multiplying or dividing by 10, 100 or 1000 — a decimal-point shift.
What grade is metric conversion?
It is a grade 4–6 measurement skill.
What are the key conversions to know?
1 km = 1000 m, 1 m = 100 cm, 1 cm = 10 mm, 1 kg = 1000 g, and 1 L = 1000 mL.
Keep practising
← MeasurementCustomary unitsMultiplying by 10, 1005th grade math