How many inches is 30 cm?

30 ÷ 2.54 = 11.81 in, just short of 12 inches.

How do I convert cm to feet and inches?

Divide by 2.54 for total inches, then divide by 12: the whole number is feet and the remainder is inches. 180 cm → 70.87 in → 5 ft 10.9 in.

Length

Centimeters to Inches

Divide centimeters by 2.54 to get inches. Show the answer as a decimal, as the nearest fraction down to 1/64, or as feet and inches.

Last updated: 2026-09-29

Key Formula

1 cm ≈ 0.3937 in

1 in = 2.54 cm

0.393701

Show as

Decimals

Need other units? Try the full unit converter →

Centimeters → Inches

Centimeters → Inches 1–40 cm
cm	in
1 cm	0.394 in
2 cm	0.787 in
3 cm	1.181 in
5 cm	1.969 in
10 cm	3.937 in
15 cm	5.906 in
20 cm	7.874 in
25 cm	9.843 in
30 cm	11.811 in
40 cm	15.748 in

Centimeters → Inches 50–180 cm
cm	in
50 cm	19.685 in
60 cm	23.622 in
70 cm	27.559 in
80 cm	31.496 in
90 cm	35.433 in
100 cm	39.370 in
120 cm	47.244 in
150 cm	59.055 in
170 cm	66.929 in
180 cm	70.866 in

Starting from inches? Convert inches to cm

How to convert cm to inches

in = cm ÷ 2.54

Dividing by 2.54 rarely gives a whole number, so pick the decimals you need or switch the converter to fractions.

30 centimeters

30 cm × (1 in / 2.54 cm)
= 11.811 in
a little under one foot (12 in)

175 cm as feet and inches

175 ÷ 2.54 = 68.898 in
68.898 ÷ 12 = 5 ft with 8.898 in left over
rounded: 5 ft 8.9 in

What is a centimeter?

A centimeter is one hundredth of a meter: the SI prefix centi means 10⁻². The meter itself is the SI base unit of length, defined by fixing the speed of light in vacuum at exactly 299 792 458 meters per second.

Because the inch is defined in metric terms (2.54 cm), one centimeter is exactly 1/2.54 in. That fraction never ends as a decimal (0.393 700 787…), which is why centimeter-to-inch answers are always rounded somewhere.

Source: BIPM — SI prefixes (retrieved 2026-09-29) / BIPM — SI base unit: metre (retrieved 2026-09-29) / NIST Guide to the SI, Appendix B.9: Factors for units listed by kind of quantity or field of science (retrieved 2026-09-29)

References

The metric side of the conversion and the factor used to divide.

BIPM — SI base unit: metre

The SI definition of the meter; a centimeter is 0.01 of it.

NIST Guide to the SI, Appendix B.9: Factors for units listed by kind of quantity or field of science

Gives inch → centimeter as exactly 2.54; converting back means dividing by that number.

FAQ

About 0.3937 in (1 ÷ 2.54 = 0.393 700 787…).