Height in Inches Calculator (cm ↔ feet and inches)

Understanding the height in inches calculator — concept and principle

This calculator converts a person's height between centimetres and feet and inches. It shows the height in total inches, in feet and inches to a tenth of an inch, to the nearest half inch, in centimetres, metres and decimal feet. It is handy for forms, dating or sports profiles, clothing sizes and medical records that use a different unit system.

Centimetres to feet and inches — with the default inputs: 5′ 8.9″.

How it is calculated

From centimetres: inches = cm ÷ 2.54
Feet = ⌊inches ÷ 12⌋; remaining inches = inches − feet × 12
From feet and inches: total inches = feet × 12 + inches; cm = inches × 2.54
Metres = inches × 0.0254; decimal feet = inches ÷ 12
Values are rounded only at the end, and rounding carries into the next foot, so 5′ 11.96″ shows as 6′ 0″ rather than 5′ 12″.

The principle

Since the 1959 international yard and pound agreement, one inch is defined as exactly 2.54 cm and one foot as exactly 30.48 cm, so the conversion involves no approximation. Heights in the US and UK are usually given as feet plus inches, which is a mixed base of 12. Converting through total inches avoids mistakes such as reading 5.75 ft as 5 ft 7.5 in.

Worked example

Default: 175 cm.

Inches = 175 ÷ 2.54 = 68.898, shown as 68.9.
Feet = ⌊68.898 ÷ 12⌋ = 5; remaining = 8.898 in: 5′ 8.9″.
Nearest half inch: 68.898 rounds to 69 in = 5′ 9″.
Metres = 1.75; centimetres 175; decimal feet = 68.898 ÷ 12 = 5.741.

How to read the result

For most forms, the nearest whole or half inch is enough; the tenth-of-an-inch value is useful when comparing measurements precisely. Height measured in the evening can be slightly lower than in the morning, because the spinal discs compress during the day, so small differences between measurements are normal.

Common mistakes

Writing 5.9 ft for 5 ft 9 in; 5.9 ft is 5 ft 10.8 in.
Rounding cm before converting, which adds error.
Measuring with shoes on or with a slouch.
Showing 12 inches instead of carrying them into the next foot.

Keep in mind: This tool converts units; it does not assess whether a height is typical or healthy for age. For children's growth, use growth charts with a health professional.

Frequently asked questions

How tall is 175 cm in feet?

About 5 feet 9 inches (5′ 8.9″).

How many cm is 6 feet?

72 inches × 2.54 = 182.88 cm.

Why is 1 inch exactly 2.54 cm?

The international agreement of 1959 defined the inch that way, ending small national differences.

Sources: NIST Special Publication 811 (2008), Appendix B (1 ft = 0.3048 m; 1 in = 2.54 cm)

Checked 9 Nov 2026. Exact definitions from NIST Special Publication 811 (2008), Appendix B: 1 ft = 0.3048 m and 12 in = 1 ft, so 1 in = 2.54 cm.

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