Work with feet, inches and fractions together
The calculator converts both measurements into total inches, performs the selected operation, then converts the result back to feet and inches plus metric units.
Feet, inches & measurement calculator
Inches Calculator
Add or subtract measurements written in feet, inches and common inch fractions. Results are normalized into total inches, decimal feet, feet-and-inches, centimetres and metres.
Interactive tool
Inches Calculator
Planning estimate only. Verify measurements, material specifications, densities, package coverage and supplier pricing before ordering.
Visual guide
How the Inches Calculator Works
See the measurement path before using the formula. The visual separates area, depth, volume and purchase units so the calculation is easier to verify.
1MeasureEnter the known dimensions or quantity.
→2CalculateThe tool applies the page formula and unit conversions.
→3PlanUse the result for ordering, pricing or comparison.
Practical guide
What to Know Before You Calculate
The number is only useful when the inputs describe the actual project. These are the assumptions that most often change the result.
Fractional inches stay practical
Common eighth-inch fractions are supported directly so construction and workshop measurements do not need to be manually converted to decimals first.
Use consistent precision
For layout and fabrication, round only at the end of the calculation. Repeated intermediate rounding can accumulate noticeable measurement error.
Calculation guide
How to Use the Inches Calculator
Convert each measurement to inches, perform the addition or subtraction, then convert the result back to the units you need. Common fractions such as 1/8, 1/4, 1/2 and 3/4 inch are handled directly.
Core formulaTotal inches = Feet × 12 + Inches + Fraction
Enter the first measurement
Use feet, inches and an optional common fraction.
Enter the second measurement
Use the same fields for the second value.
Choose add or subtract
The tool normalizes both values into inches first.
Read multiple units
The answer is returned in feet/inches, total inches, decimal feet, centimetres and metres.
Worked example
Inches Calculator Example
3 ft 6½ in + 2 ft 3¼ in = 69.75 total inches, which is 5 ft 9¾ in.
Reference values
Inches Calculator Reference Table
Use this table for quick planning checks. Calculator inputs remain the better choice when your dimensions, depth, density, waste or product coverage differ.
| Feet | Inches | Centimetres |
|---|---|---|
| 1 ft | 12 in | 30.48 cm |
| 2 ft | 24 in | 60.96 cm |
| 3 ft | 36 in | 91.44 cm |
| 4 ft | 48 in | 121.92 cm |
| 5 ft | 60 in | 152.40 cm |
| 6 ft | 72 in | 182.88 cm |
| 7 ft | 84 in | 213.36 cm |
| 8 ft | 96 in | 243.84 cm |
| 9 ft | 108 in | 274.32 cm |
| 10 ft | 120 in | 304.80 cm |
| 11 ft | 132 in | 335.28 cm |
| 12 ft | 144 in | 365.76 cm |
| 13 ft | 156 in | 396.24 cm |
| 14 ft | 168 in | 426.72 cm |
| 15 ft | 180 in | 457.20 cm |
| 16 ft | 192 in | 487.68 cm |
| 17 ft | 204 in | 518.16 cm |
| 18 ft | 216 in | 548.64 cm |
| 19 ft | 228 in | 579.12 cm |
| 20 ft | 240 in | 609.60 cm |
| 21 ft | 252 in | 640.08 cm |
| 22 ft | 264 in | 670.56 cm |
| 23 ft | 276 in | 701.04 cm |
| 24 ft | 288 in | 731.52 cm |
| 25 ft | 300 in | 762.00 cm |
| 26 ft | 312 in | 792.48 cm |
| 27 ft | 324 in | 822.96 cm |
| 28 ft | 336 in | 853.44 cm |
| 29 ft | 348 in | 883.92 cm |
| 30 ft | 360 in | 914.40 cm |
| 31 ft | 372 in | 944.88 cm |
| 32 ft | 384 in | 975.36 cm |
| 33 ft | 396 in | 1,005.84 cm |
| 34 ft | 408 in | 1,036.32 cm |
| 35 ft | 420 in | 1,066.80 cm |
| 36 ft | 432 in | 1,097.28 cm |
| 37 ft | 444 in | 1,127.76 cm |
| 38 ft | 456 in | 1,158.24 cm |
| 39 ft | 468 in | 1,188.72 cm |
| 40 ft | 480 in | 1,219.20 cm |
| 41 ft | 492 in | 1,249.68 cm |
| 42 ft | 504 in | 1,280.16 cm |
| 43 ft | 516 in | 1,310.64 cm |
| 44 ft | 528 in | 1,341.12 cm |
| 45 ft | 540 in | 1,371.60 cm |
| 46 ft | 552 in | 1,402.08 cm |
| 47 ft | 564 in | 1,432.56 cm |
| 48 ft | 576 in | 1,463.04 cm |
| 49 ft | 588 in | 1,493.52 cm |
| 50 ft | 600 in | 1,524.00 cm |
| 51 ft | 612 in | 1,554.48 cm |
| 52 ft | 624 in | 1,584.96 cm |
| 53 ft | 636 in | 1,615.44 cm |
| 54 ft | 648 in | 1,645.92 cm |
| 55 ft | 660 in | 1,676.40 cm |
| 56 ft | 672 in | 1,706.88 cm |
| 57 ft | 684 in | 1,737.36 cm |
| 58 ft | 696 in | 1,767.84 cm |
| 59 ft | 708 in | 1,798.32 cm |
| 60 ft | 720 in | 1,828.80 cm |
| 61 ft | 732 in | 1,859.28 cm |
| 62 ft | 744 in | 1,889.76 cm |
| 63 ft | 756 in | 1,920.24 cm |
| 64 ft | 768 in | 1,950.72 cm |
| 65 ft | 780 in | 1,981.20 cm |
| 66 ft | 792 in | 2,011.68 cm |
| 67 ft | 804 in | 2,042.16 cm |
| 68 ft | 816 in | 2,072.64 cm |
| 69 ft | 828 in | 2,103.12 cm |
| 70 ft | 840 in | 2,133.60 cm |
| 71 ft | 852 in | 2,164.08 cm |
| 72 ft | 864 in | 2,194.56 cm |
| 73 ft | 876 in | 2,225.04 cm |
| 74 ft | 888 in | 2,255.52 cm |
| 75 ft | 900 in | 2,286.00 cm |
| 76 ft | 912 in | 2,316.48 cm |
| 77 ft | 924 in | 2,346.96 cm |
| 78 ft | 936 in | 2,377.44 cm |
| 79 ft | 948 in | 2,407.92 cm |
| 80 ft | 960 in | 2,438.40 cm |
| 81 ft | 972 in | 2,468.88 cm |
| 82 ft | 984 in | 2,499.36 cm |
| 83 ft | 996 in | 2,529.84 cm |
| 84 ft | 1008 in | 2,560.32 cm |
| 85 ft | 1020 in | 2,590.80 cm |
| 86 ft | 1032 in | 2,621.28 cm |
| 87 ft | 1044 in | 2,651.76 cm |
| 88 ft | 1056 in | 2,682.24 cm |
| 89 ft | 1068 in | 2,712.72 cm |
| 90 ft | 1080 in | 2,743.20 cm |
| 91 ft | 1092 in | 2,773.68 cm |
| 92 ft | 1104 in | 2,804.16 cm |
| 93 ft | 1116 in | 2,834.64 cm |
| 94 ft | 1128 in | 2,865.12 cm |
| 95 ft | 1140 in | 2,895.60 cm |
| 96 ft | 1152 in | 2,926.08 cm |
| 97 ft | 1164 in | 2,956.56 cm |
| 98 ft | 1176 in | 2,987.04 cm |
| 99 ft | 1188 in | 3,017.52 cm |
| 100 ft | 1200 in | 3,048.00 cm |
People also ask
Inches Calculator FAQs
Overlapping questions are consolidated so each answer covers a distinct calculation or planning issue.
How to do inches on a calculator?
Convert feet to inches by multiplying by 12, convert any inch fraction to a decimal, then add or subtract the values as normal numbers.
How are inches calculated?
There are 12 inches in one foot. A feet-and-inches measurement can be converted to total inches using feet × 12 + inches.
What is 3/4 in inches?
Three quarters of an inch is 0.75 inch.
What is 1/4 into inches?
One quarter of an inch is 0.25 inch.
Is 3/4 and 1 inch the same?
No. Three quarters of an inch is 0.75 inch, which is 0.25 inch less than one full inch.
Methodology & source note
Formulas are shown on the page and variable assumptions are exposed as inputs where they affect the result. Unit relationships are checked against NIST measurement references. Material density, packaging, product coverage and pricing should be verified with the supplier for the material actually being purchased.