Ruler — Object Measuring 10 cm — free printable diagram

How long is 10 cm?

The object in this illustration measures 10 centimetres. It starts at the 0 mark on the ruler and ends at 10, so its length is 10 cm — which is the same as 100 millimetres, or about 3.94 in.

Centimetres

10 cm

Millimetres

100 mm

Metres

0.1 m

Inches

≈3.94 in

• Measure from the 0 mark, not from the end of the ruler. Most rulers have a small margin before the scale begins, and starting there is the commonest source of a wrong answer.
• Each numbered mark is 1 centimetre and each small mark between them is 1 millimetre, so 10 mm = 1 cm and 10 cm = 100 mm.
• To convert centimetres to millimetres, multiply by 10: 10 × 10 = 100 mm. To go the other way, divide by 10.
• To convert centimetres to metres, divide by 100: 10 ÷ 100 = 0.1 m.
• One inch is exactly 2.54 cm, so 10 cm ÷ 2.54 is about 3.94 in.