Convert inches to centimetres

Formula: cm = in × 2.54

in to cm quick reference table

Everyday in values, converted

• 12 in = 30.48 cm — one foot.
• 27 in = 68.58 cm — a common monitor diagonal.
• 6 in = 15.24 cm — a phone-sized measurement.

Where in to cm comes up

Length conversions come up in DIY and construction, screen and print sizing, running distances, and clothing or furniture measurements ordered from abroad. Mixed-unit plans are the usual reason a cut ends up wrong.

Doing in to cm in your head

Multiply by 2.5 and add a touch. 10 gives 25 against an exact 25.4.

Precision and rounding

One inch is exactly 2.54 centimetres under the current definitions of both units, so the only judgement call is how many digits you keep. Two decimal places is already finer than most household scales and tape measures can read, while engineering and medical work usually keeps the full factor and rounds once at the end rather than at every step.