About the Feet and Inches Calculator
This feet and inches calculator does tape-measure math without converting by hand. Enter a length in feet, inches and a fraction of an inch, pick an operation, and it returns the answer the way you would read it off a tape — for example 9 ft 3 3/4 in — along with total inches, decimal feet, meters and centimeters.
Carpenters, framers, cabinet makers and DIYers use it to add up wall runs, subtract a cut from a board, split a length into equal spaces, or scale a measurement. Adding and subtracting uses a second length; multiplying and dividing use a plain number, such as the number of equal pieces.
Results are rounded to the nearest 1/16 inch by default, which matches most tape measures; you can switch to 1/32 for fine work or 1/8 and 1/4 for rough framing. Decimal feet, meters and total inches are shown unrounded.
How to use the feet and inches calculator
- 1Enter the first length as feet, inches and a fraction.
- 2Choose add, subtract, multiply or divide.
- 3Enter the second length, or the number to multiply or divide by.
- 4Pick the rounding precision that matches your tape measure.
- 5Read the result in feet and inches, or use the decimal and metric values.
Formula and method
Each length is converted to a single number of inches (feet × 12 + whole inches + fraction). The operation is applied to those inch values: two lengths are added or subtracted, or one length is multiplied or divided by a plain number.
To display the answer, the total is rounded to the nearest selected fraction (1/16 inch by default), split into whole feet (total ÷ 12, rounded down) and remaining inches, and the fractional part is reduced to lowest terms — for example 12/16 becomes 3/4. Metric values use the exact definition 1 inch = 2.54 cm.
- in
- Total length in inches
- mod
- Remainder after dividing by 12
Worked examples
5' 7 1/2" + 3' 8 1/4"
5 ft 7 1/2 in is 67.5 inches and 3 ft 8 1/4 in is 44.25 inches. Together they make 111.75 inches, which is 9 feet (108 in) and 3 3/4 inches.
12' minus 7' 5 3/8"
A 12 ft board is 144 inches. Cutting off 7 ft 5 3/8 in (89.375 in) leaves 54.625 inches, which reads as 4 ft 6 5/8 in on the tape.
Divide 10' 3" into 4 equal spaces
10 ft 3 in is 123 inches. Dividing by 4 gives 30.75 inches per space, or 2 ft 6 3/4 in (78.1 cm).
Six pieces at 2' 7 1/2"
2 ft 7 1/2 in is 31.5 inches. Six of them total 189 inches, which is exactly 15 ft 9 in of material.
Frequently asked questions
How do you add feet and inches?+
Add the inches together and the feet together. If the inches total 12 or more, carry 12 inches over as one foot. For example 5′ 9″ + 2′ 6″ = 7′ 15″ = 8′ 3″.
How do I convert inches to feet and inches?+
Divide the inches by 12. The whole number is the feet and the remainder is the inches: 111.75 inches ÷ 12 = 9 remainder 3.75, so 9 ft 3 3/4 in.
What is 1/16 of an inch in decimal?+
1/16 inch is 0.0625 inches (about 1.59 mm). Other common marks: 1/8 = 0.125, 1/4 = 0.25, 3/8 = 0.375, 1/2 = 0.5, 5/8 = 0.625, 3/4 = 0.75 and 7/8 = 0.875.
How do I convert feet and inches to meters?+
Convert to total inches first, then multiply by 0.0254. For example 6 ft 2 in = 74 inches × 0.0254 = 1.8796 meters.
How do I divide a length into equal spaces?+
Choose Divide and enter the number of spaces. For evenly spaced balusters or shelves, remember to subtract the width of the pieces themselves first, or use a dedicated spacing calculator.