Learn the exact conversion between centimeters and inches with quick mental math tips, common reference points, and height conversion examples.
Step-by-Step Guide
Know the conversion factor
1 inch = 2.54 centimeters (exact, by international definition). Therefore 1 cm = 0.393701 inches.
Convert cm to inches
Divide centimeters by 2.54. Examples: 30 cm = 11.81 in. 100 cm (1 m) = 39.37 in. 170 cm = 66.93 in (about 5 ft 7 in).
Convert inches to cm
Multiply inches by 2.54. Examples: 12 in (1 ft) = 30.48 cm. 72 in (6 ft) = 182.88 cm. 5 in = 12.7 cm.
Convert height (feet + inches to cm)
Convert feet to inches first (1 ft = 12 in), add the remaining inches, then multiply by 2.54. Example: 5'10" = (5×12 + 10) = 70 in × 2.54 = 177.8 cm.
Use the Length Converter
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Frequently Asked Questions
Q: How many cm is 5 feet 9 inches?
A: 5 ft 9 in = 69 inches × 2.54 = 175.26 cm.
Q: Why is 1 inch exactly 2.54 cm?
A: This was set by international agreement in 1959 to unify the US and UK inch, which were previously slightly different values.
Q: What are common everyday reference points?
A: A standard door is about 200 cm (79 in). A credit card is 85.6 mm (3.37 in) wide. An A4 paper sheet is 29.7 cm (11.69 in) tall.