Centimetres vs Inches
Side-by-side comparison, when-to-use-each guide, and instant conversion. Reviewed for 2026.
All scientific work, most of the world for everyday measurements, screen sizes in some markets.
US construction, US sewing, UK building trade, screen sizes (TV/monitor diagonals), pipe and bolt sizes worldwide.
| Aspect | Centimetres | Inches |
|---|---|---|
| Definition | SI: 1/100 of a metre | Exactly 25.4 mm by international agreement |
| Symbol | cm | in or " |
| Common precision | mm (1/10 cm) | 1/16 inch or 1/32 inch in trades |
| Body height | Used in most countries | UK and US default for personal height |
Frequently asked
Is 1 inch exactly 2.54 cm?
Yes, exactly. Since 1959, the international inch has been defined as 25.4 mm by treaty.
What's 6 foot in cm?
6 feet = 72 inches = 182.88 cm, universally rounded to 183 cm in clinical records. Common heights: 5'6" = 167.6 cm, 5'8" = 172.7 cm, 5'10" = 177.8 cm, 6'0" = 182.9 cm, 6'2" = 187.9 cm. The UK uses cm for medical records, but feet/inches in everyday conversation.
Frequently asked questions
Is 1 inch exactly 2.54 cm?
Yes, exactly. Since 1959, the international inch has been defined as 25.4 mm by treaty.
What's 6 foot in cm?
6 feet = 72 inches = 182.88 cm, universally rounded to 183 cm in clinical records. Common heights: 5'6" = 167.6 cm, 5'8" = 172.7 cm, 5'10" = 177.8 cm, 6'0" = 182.9 cm, 6'2" = 187.9 cm. The UK uses cm for medical records, but feet/inches in everyday conversation.