Formats you can enter
| You type | Means |
|---|
| 5' 6 3/8" | 5 feet 6⅜ inches |
| 5ft 6in | 5 feet 6 inches |
| 10' | 10 feet |
| 6-1/2" | 6½ inches |
| 3/4 | ¾ inch |
| 12.5 | 12.5 inches |
Worked example
5' 8¼" + 3' 7⅝": the inches are 8¼ + 7⅝ = 15⅞, and the feet are 5 + 3 = 8. Since 15⅞ inches is 1 foot 3⅞ inches, the answer is 9' 3⅞" (111.875 inches).
Fractions of an inch as decimals
| Fraction | Decimal | Fraction | Decimal |
|---|
| 1/16" | 0.0625 | 9/16" | 0.5625 |
| 1/8" | 0.1250 | 5/8" | 0.6250 |
| 3/16" | 0.1875 | 11/16" | 0.6875 |
| 1/4" | 0.2500 | 3/4" | 0.7500 |
| 5/16" | 0.3125 | 13/16" | 0.8125 |
| 3/8" | 0.3750 | 7/8" | 0.8750 |
| 7/16" | 0.4375 | 15/16" | 0.9375 |
| 1/2" | 0.5000 | 1/1" | 1.0000 |
Planning steps? The stair calculator shows risers and runs in feet and inches. For lumber volume, use the board foot calculator, and for floor area the square footage calculator.
Last reviewed October 2026.
Frequently asked questions
How do I type feet and inches?
Use an apostrophe for feet and a quote mark for inches, like 5' 6 3/8". You can also write 5ft 6in, 6-1/2", 3/4" or a plain decimal number of inches like 12.5. Negative numbers work too.
How do you add feet and inches by hand?
Add the inches first, including fractions. If the total is 12 inches or more, carry each 12 inches over as 1 foot. Then add the feet. For example, 5' 8" + 3' 7" = 8' 15" = 9' 3".
What does "round to the nearest 1/16" mean?
Tape measures are usually marked in sixteenths of an inch. The calculator rounds each answer to the nearest mark you choose (1/2, 1/4, 1/8, 1/16 or 1/32) and simplifies the fraction, so 8/16 shows as 1/2.
Can I multiply or divide a length?
Yes. Choose × or ÷ and type a plain number as the second value, for example 7' 4" ÷ 3 to split a board into three equal pieces.
How do I convert inches to feet?
Divide the inches by 12. The whole number is feet and the remainder is inches: 75 inches is 6 feet with 3 left over, so 6' 3". The calculator also shows the result in decimal feet, centimeters and meters.