Feet to Inches Calculator
Multiply the number of feet by 12 to convert to inches, since 1 foot equals exactly 12 inches by definition.
Quick Answer
Multiply the number of feet by 12 to convert to inches, since 1 foot equals exactly 12 inches by definition.
Feet to Inches Calculator
Enter a feet-and-inches measurement below for an instant conversion, then see the formula, worked example, and common mistakes.
Enter your values and click calculate.
How to Use This Calculator
This is the main feet value from your tape measure or plan.
If your measurement is 5 feet 6 inches, enter 5 in the feet field and 6 in the additional-inches field.
The calculator multiplies feet by 12 and adds the extra inches for the full measurement in inches.
Divide any inches value by 12 to confirm the decimal-feet equivalent.
Formula
Inches = (Feet x 12) + Additional inches. Feet = Inches / 12.
Reference Table: Feet to Inches
| Feet | Inches |
|---|---|
| 1 ft | 12 in |
| 3 ft (1 yard) | 36 in |
| 5 ft | 60 in |
| 10 ft | 120 in |
Common Mistakes to Avoid
- Forgetting to add extra inches (e.g., 5 feet 6 inches) before multiplying — convert the whole measurement, not just the whole-foot part.
- Mixing up feet-inches notation (5’6″) with decimal feet (5.5 ft) — 5’6″ means 5 feet plus 6 inches, which is 5.5 decimal feet, not 5.06.
- Using an approximate conversion factor instead of the exact, definition-based value of 12 inches per foot.
- Rounding intermediate results before the final conversion, which compounds small errors in multi-step woodworking measurements.
When the Estimate May Be Wrong
This is an exact mathematical conversion (1 ft = 12 in by definition), so it is never “wrong” as a formula — the only source of error is an inaccurate input measurement. Always double-check your tape measure reading, especially when combining feet and fractional inches for woodworking cut lists.
FAQs
How many inches are in a foot?
There are exactly 12 inches in 1 foot — this is an exact, defined conversion, not an approximation.
How do I convert 5 feet 6 inches to inches?
Multiply the feet by 12 and add the extra inches: (5 x 12) + 6 = 66 inches.
How do I convert inches back to feet?
Divide the number of inches by 12 to get decimal feet (e.g., 66 inches / 12 = 5.5 feet, or 5 feet 6 inches).
Why do woodworkers need to convert between feet and inches?
Lumber is typically sold and measured in feet (board length) but cut and joined using inch and fractional-inch measurements, so accurate conversion prevents costly cutting mistakes.
Sources and Methodology
The foot-to-inch conversion (1 ft = 12 in) is an exact, internationally defined unit relationship (based on the international foot standardized in 1959), not an approximation, so this calculator uses the exact factor of 12 with no rounding error introduced by the conversion itself.
