Use a feet and inches calculator to add, subtract, multiply, or divide compound imperial lengths, enter tape-measure fractions.
Last updated
Use this feet and inches calculator for arithmetic first, conversion second This feet and inches calculator works as an add feet and inches calculator, a divide feet and inches calculator for equal cuts, and a convert inches to feet and inches helper after the arithmetic is done. Enter decimal inches or tape-measure fractions like 7 1/4 directly in the inches fields when you need construction-style input.
Quick presets
Start with a common layout job, then adjust the numbers to match your own run lengths.
Measurement A
Inches fields accept decimals or fractions such as 3/8, 7 1/4, or 10-1/2.
Operation
Measurement B
Best fit
Use this tool when you need feet-and-inches arithmetic first and metric output second,
such as layout changes, equal cuts, or field-to-plan checks.
Result
7 ft 9 in
Combined run length in imperial and metric formats.
Total inches
93
Decimal feet
7.75
Centimetres
236.22
Metres
2.36
Millimetres
2,362.2
Nearest 1/16 mark
7 ft 9 in
Tape-measure ready result The exact result is 7 ft 9 in. The nearest 1/16-inch tape mark is 7 ft 9 in, which keeps the rounding gap to about 0 in.
Fraction-ready output
Tape mark
Rounded result
Gap from exact result
1/8
7 ft 9 in
0 in
1/16
7 ft 9 in
0 in
1/32
7 ft 9 in
0 in
1/64
7 ft 9 in
0 in
Working note
Addition is useful for combining wall runs, trim pieces, or field measurements before you switch to decimal feet, metric output, or tape-ready fractions.
Feet and inches calculator: add, subtract, divide, and convert inches to feet and inches
A feet and inches calculator helps when the measurement itself is already in compound imperial notation and the next task is arithmetic, not just unit conversion.
Why compound imperial lengths are awkward by hand
Feet-and-inches notation is easy to read on tape measures and plans, but it is slower to manipulate mentally because inches have to be carried into feet every time they cross 12. That makes simple arithmetic error-prone, especially when several lengths are combined or when one total run is split into equal parts.
A dedicated calculator removes that carry problem by translating each measurement into total inches first, doing the arithmetic there, and then rebuilding the result as feet and inches. That keeps the familiar imperial format while still exposing the decimal-foot and metric equivalents for the next workflow.
The working method behind the result
The underlying method is straightforward. First convert the entered feet-and-inches measurement into total inches. Then apply the chosen arithmetic operation. Finally, split the result back into whole feet plus the remaining inches and derive decimal feet, centimetres, and metres from the same base length.
Because the metric outputs come from the same computed total inches, the imperial and metric views stay aligned. That is useful when a job starts in feet and inches but the purchased materials, supplier sheets, or design software use metric length notation.
Total inches = (feet × 12) + inches
Base conversion used before any arithmetic is applied.
Decimal feet = total inches ÷ 12
Simplified imperial output for estimating, pricing, and software entry.
Metres = total inches × 0.0254
Exact international-inch relationship used for metric output.
When decimal feet or centimetres are more useful than compound notation
Compound feet-and-inches output is best when you are reading directly from a tape or keeping the result in an imperial build workflow. Decimal feet are often easier for quoting, take-offs, and spreadsheet work, while centimetres and metres are more useful when a project crosses into metric product specs or drawings.
That is why the live tool shows all of those formats at once. It lets the same computed length stay readable in the notation the next person or system actually expects, without making you recalculate from scratch.
Why fractional inches matter in a construction calculator
Many site and workshop measurements are not entered as clean decimals. Tape measures are usually read in eighths, sixteenths, or thirty-seconds of an inch, so an input like 10 1/2 in or 7 1/4 in is often more natural than 10.5 or 7.25. A stronger ft inch calculator should therefore understand tape-measure style fractional inches instead of forcing the user to translate them into decimals first.
That is also why the result should not stop at a raw decimal. If the exact calculation returns 2 ft 4.8 in, the next practical question is usually which tape mark to use on site. Showing the nearest 1/8, 1/16, 1/32, and 1/64 inch versions turns the calculator into a layout aid instead of just a converter.
Worked examples: adding runs and dividing a total span into equal cuts
Suppose two wall runs measure 8 ft 4 in and 3 ft 10 1/2 in. A manual method would convert both into inches, add them, then carry the overflow back into feet. The calculator does that automatically and gives the combined result in feet and inches, decimal feet, centimetres, and metres from the same base total.
For equal cuts, imagine dividing 12 ft into 5 sections. The exact result is 28.8 in per section, which is 2 ft 4.8 in. A better divide feet and inches calculator should then show the nearest tape-ready fractions, because the person using the result often needs a quick 1/16 or 1/32 mark, or a finer 1/64 check, rather than a decimal inch alone.
When to use this page instead of a plain inch-to-foot converter
A plain inch to foot converter or foot in inches calculator is enough when you already have a single decimal value and only need a unit switch. This page is broader because it handles add-subtract feet inches workflow, equal cuts, repeated lengths, and convert-inches-to-feet-and-inches tasks from the same interface.
That makes it more useful for real build and layout work, where the next step is rarely just a conversion. People usually need arithmetic first, then a decimal-feet number for a quote, then a tape-measure-friendly fraction for a cut list. Keeping those outputs together reduces transcription mistakes.
Frequently asked questions
How do I add feet and inches correctly?
Convert both measurements into total inches, add them, and then carry one foot for every 12 inches in the result. This calculator performs that carry automatically and also shows the decimal-foot and metric equivalents.
Can I divide a length into equal sections?
Yes. Enter the total length as measurement A, switch to divide mode, and use the divisor input for the number of equal parts. The tool returns each section in feet and inches as well as decimal feet and metric output.
Why show decimal feet as well as feet and inches?
Because many estimating sheets, quotes, and software tools accept decimal feet more easily than compound notation. Both values describe the same length; they are just written differently.
Can the result be negative?
Yes, if you subtract a larger measurement from a smaller one. The calculator keeps the sign visible so you can spot that the arithmetic direction produced a deficit rather than an added run length.
Can I enter fractional inches like 7 1/4 or 10-1/2?
Yes. The inches fields accept common tape-measure styles such as 3/8, 7 1/4, or 10-1/2 as well as decimals like 7.25. That makes the page more practical when you are copying dimensions directly from a plan or a physical tape.
How do I convert inches to feet and inches?
Divide the total inches by 12. The whole-number part is feet and the remainder is inches. For example, 29 in = 2 ft 5 in because 24 in makes 2 ft and 5 in remains. This calculator does that automatically after any arithmetic result.
Why does the calculator show 1/8, 1/16, 1/32, and 1/64 results too?
Those rows help you move from an exact decimal answer to a tape-ready mark. A decimal like 4.8 in is mathematically clear, but on site many people need the nearest 1/16 or 1/32 mark to lay out equal cuts, while finer work may need a 1/64 check.
When should I use decimal feet instead of feet and inches?
Use decimal feet when the next step is estimating, quoting, spreadsheet work, or software entry. Use feet and inches when the next step is reading directly from a tape measure, marking stock, or checking dimensions against drawings that already use compound imperial notation.
Is this page the same as a height converter?
No. Height converters focus on body-height formats such as centimetres, metres, and feet and inches. This page is for imperial length arithmetic and construction-style measurement workflow, including adding runs, subtracting offsets, multiplying repeated lengths, and dividing spans into equal sections.
