CM to Inches Converter
Centimeters ⇄ inches, with feet & fractions
How to Use
- 1Enter the length you want to convert.
- 2Pick the direction: cm to inches, or inches to cm.
- 3Choose the decimal precision you need.
- 4Read the answer plus feet-and-inches and the nearest fraction.
Conversion Formula
- Exact definition1 inch = 2.54 cm
- cm → inchesin = cm ÷ 2.54
- Inches → cmcm = in × 2.54
- Feet & inches1 ft = 12 in = 30.48 cm
Quick Examples
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Everything about CM to Inches
The exact 2.54 rule, height conversions, and a chart of everyday values.
Centimeters to inches is the most common metric to imperial conversion of all: heights, screen sizes, clothing, furniture and luggage limits all cross between the two systems. The rule is exact: one inch is defined as precisely 2.54 centimeters. This cm to inches converter also shows feet-and-inches (perfect for heights) and the nearest ruler fraction.
Height trick: 170 cm ÷ 2.54 = 66.93 in. Divide by 12: 5 remainder 6.93, so so 170 cm is 5 ft 6.9 in, usually said as "five-seven".
How the conversion works
Divide centimeters by 2.54 to get inches: 30 cm ÷ 2.54 = 11.811 in, which is why a 30 cm school ruler is marked 12 inches on the other edge (it is actually 30.48 cm). Multiply inches by 2.54 to go back: 12 × 2.54 = 30.48 cm.
Everyday values
| Centimeters | Inches | Feet & inches |
|---|---|---|
| 2.54 cm | 1 in | — |
| 10 cm | 3.9370 in | — |
| 30 cm | 11.8110 in | ≈ 1 ft |
| 50 cm | 19.6850 in | 1 ft 7.7 in |
| 100 cm | 39.3701 in | 3 ft 3.4 in |
| 160 cm | 62.9921 in | 5 ft 3.0 in |
| 170 cm | 66.9291 in | 5 ft 6.9 in |
| 180 cm | 70.8661 in | 5 ft 10.9 in |
Getting it right
- 1Heights use feet + inches
Convert to total inches first, then split: whole feet = total ÷ 12, remainder = leftover inches.
- 2Screens are diagonal
A "55-inch" TV is 55 in ≈ 139.7 cm across the diagonal, not the width.
- 3Quick mental check
Inches ≈ cm × 0.4. So 50 cm ≈ 20 in, and the exact answer is 19.685, close enough to spot errors.
- 4Don't confuse cm and mm
1 cm = 10 mm. If a spec sheet says 305 mm, that is 30.5 cm = 12.01 in.
Frequently Asked Questions
How many inches is 1 cm?
1 cm = 0.3937 inches (exactly 1 ÷ 2.54). Ten centimeters is 3.937 inches, and 100 cm (one meter) is 39.37 inches.
How do I convert cm to inches by hand?
Divide the centimeter value by 2.54. Example: 45 cm ÷ 2.54 = 17.7165 in. Going the other way, multiply inches by 2.54: 17.72 × 2.54 = 45.01 cm.
How do I convert cm to feet and inches?
Divide cm by 2.54 to get total inches, then divide by 12: the whole part is feet and the remainder is inches. Example: 175 cm → 68.898 in → 5 ft 8.9 in.
Is 2.54 exact?
Yes. One inch has been defined as exactly 2.54 cm since 1959, so cm to inch conversions carry no approximation at all, only the rounding you apply to the result.
What is 30 cm in inches?
30 cm = 11.811 inches, just under one foot. A standard 30 cm ruler and a 12-inch (30.48 cm) ruler differ by about 5 mm.
Is this cm to inches converter free and does it work on mobile?
Yes. It is 100% free, no sign-up, and fully responsive in any modern browser. All math runs locally on your device; nothing you enter is saved or transmitted.