FitterMaster Feet-inches-sixteenths calculator: add lengths and convert to a fraction
Tape Math adds or subtracts two feet-inches-sixteenths lengths, and separately turns a decimal-inch or millimetre value into the nearest 1/16" or 1/32" fraction. It is free, and Length A and Length B always stay imperial, even when the rest of FitterMaster is set to metric.
What does Tape Math do?
It is two tools on one screen: adding or subtracting two tape measurements entered as feet, inches and sixteenths, and converting a single decimal-inch or millimetre number to the nearest fraction, decimal, millimetres and feet-inch. Small as it is, this is one of the most-used screens in the app — faster than the calculator app's keypad for anything with a fraction in it.
How do you add feet and inches in FitterMaster?
- Open Tape Math under Tools on the main screen.
- Set Length A with the feet, inch and sixteenth steppers.
- Set Length B the same way.
- Read A + B and A − B directly below.
- Tap Copy or Share on the Equivalents card to send a result.
Worked example: adding two lengths
| Result | Value | How |
|---|---|---|
| A + B | 3'-0-7/8" | 31.5" + 5.375" = 36.875" |
| A − B | 2'-2-1/8" | 31.5" − 5.375" = 26.125" |
Converting decimal inches or millimetres to a fraction
Below the add/subtract card, type a value into Decimal inches or Millimetres. The Equivalents card shows it as Nearest 1/16, Nearest 1/32, Decimal, Millimetres and Feet-inch all at once.
| You type | Nearest 1/16 | Decimal | Millimetres |
|---|---|---|---|
| 1.3 in Decimal inches | 1-5/16" | 1.300" | 33.0 mm |
| 100 in Millimetres | 3-15/16" | 3.937" | 100.0 mm |
Tips and common mistakes
- Length A and Length B are always feet-inches, even when the rest of the app is set to metric in Settings — this screen does not switch.
- For thirty-seconds instead of sixteenths on the fraction rows, change Fraction to 1/32" in Settings under Display; the entry steppers still move in sixteenths.
- A negative subtraction (B longer than A) still needs checking by hand: read the sign on A − B before you cut.
Questions and answers
How do I add feet and inches on my iPhone?
Can it convert millimetres to a fraction of an inch?
Does the metric setting change Tape Math?
Is Tape Math free?
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