Ruler — Object Measuring 9 cm — free printable diagram

How long is 9 cm?

The object in this illustration measures 9 centimetres. It starts at the 0 mark on the ruler and ends at 9, so its length is 9 cm — which is the same as 90 millimetres, or about 3.54 in.

Centimetres

9 cm

Millimetres

90 mm

Metres

0.09 m

Inches

≈3.54 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 9 cm = 90 mm.
• To convert centimetres to millimetres, multiply by 10: 9 × 10 = 90 mm. To go the other way, divide by 10.
• To convert centimetres to metres, divide by 100: 9 ÷ 100 = 0.09 m.
• One inch is exactly 2.54 cm, so 9 cm ÷ 2.54 is about 3.54 in.