Converting from a smaller unit to a larger one

When you go from a smaller unit (mm, cm) to a larger one (m, km), you always divide. The reason: a larger unit is a longer measuring stick, so the same distance fits into fewer of them.

The rule

To convert from a smaller unit to a larger unit, divide by the conversion factor.

Metric examples

Imperial examples

Whole-number results only

To get a whole number out, the input must be a multiple of the conversion factor. Our exercises always pick the input that way, so you can practise the calculation without having to deal with decimals.

In practice it means:

• $4000\text{m}$ converts cleanly to $4\text{km}$ ✓
• $4500\text{m}$ would give $4.5\text{km}$ — not a whole number, so it would not appear in this exercise.

Quick mental check

A useful trick: count the zeros in the conversion factor and remove the same number of zeros from the input.

• $5000\text{m}÷1000=5\text{km}$ — three zeros disappear.
• $700\text{cm}÷100=7\text{m}$ — two zeros disappear.

If the input does not end in enough zeros, the result will not be a whole number — and you should check the input again.

Common pitfalls

• Forgetting which direction divides. Smaller → larger means you can fit fewer of the longer sticks, so the count gets smaller — and that means dividing.
• Misreading factors. $1\text{km}$ is $1000\text{m}$, not $100$. The big jump in the metric system is exactly here.
• Imperial mile: 1 760 yards is the trickiest factor. It is worth memorising.

Read more

• Length unit conversions – guide
• Metric system
• Imperial units
• Converting larger to smaller

Practise

• Convert smaller to larger (metric)
• Imperial – smaller to larger
• Fill in the unit