Feet and Inches Calculator

Do math with feet and inches the way carpenters need it — add or subtract two lengths, or multiply and divide by a number.

How to use the Feet and Inches Calculator

Enter the first length in feet and inches.
Choose an operation.
Enter the second length or the number.

How it works

The calculator converts everything to inches, does the arithmetic, then converts back: 5′ 8″ + 3′ 7″ = 68″ + 43″ = 111″ = 9′ 3″. Results are rounded to the nearest 1/16 inch, the finest mark on most tape measures, and also shown in decimal feet and metric.

Inches to feet

Inches	Feet & inches	Decimal feet
12	1′ 0″	1
18	1′ 6″	1.5
24	2′ 0″	2
30	2′ 6″	2.5
36	3′ 0″	3
48	4′ 0″	4
60	5′ 0″	5
72	6′ 0″	6
96	8′ 0″	8
120	10′ 0″	10

Frequently asked questions

What is 5 ft 8 in plus 3 ft 7 in?

9 ft 3 in.

How do I add feet and inches?

Add the inches; every 12 inches carries over as a foot.

How many inches is 6 ft 2 in?

74 inches.

How do I divide a board into equal parts?

Use the divide operation — e.g. 8′ ÷ 3 = 2′ 8″.