Feet+Inches to Feet Converter

How to convert feet+inches to decimal feet?

To convert feet and inches to decimal feet, divide the inches by 12 (since 1 foot = 12 inches exactly), then add to the feet value. The factor 12 is exact under the 1959 international yard-and-pound agreement. Note that some inch counts produce repeating decimals (e.g., 10/12 = 0.8333...).

d_(ft) = d_(ft) + d_(in) / 12

Example

Convert 5 feet 6 inches to decimal feet:

d_(ft) = 5ft + 6in / 12 = 5ft + 0.5ft = 5.5ft

How many inches in a foot?

Exactly 12 inches, by definition since the 1959 international yard-and-pound agreement.

1 ft = 12 in

How do I convert inches to decimal feet?

Divide the number of inches by 12. For example: 6 inches ÷ 12 = 0.5 ft. To convert feet+inches together, do inches ÷ 12 first, then add to feet.

Why is 5'10" written as 5.8333 ft and not 5.83 ft?

Because 10/12 is a repeating decimal (0.833...). Truncating at two decimals introduces an error of about 0.003 ft = 0.04 in = 1 mm. For most construction this is fine; for precision metalwork or stone-cutting, carry four or more decimal places.

What is a Foot?

The foot is a US-customary unit of length, defined as exactly 0.3048 meter under the 1959 international agreement. It equals 12 inches or 1/3 yard. The unit is dominant in US construction, real estate, and aviation.

What is an Inch?

The inch is one-twelfth of a foot, defined as exactly 0.0254 meter. The name comes from the Roman uncia (twelfth). It remains the principal small-length unit in US construction, electronics, and screen dimensions.

Popular feet+inches to feet conversion table