Use feet and inches to combine a mixed measurement. Use inches to fraction to express decimal inches on a chosen fraction grid.
The two tasks
| Feet and inches | Inches to fraction | |
|---|---|---|
| Inputs | Feet and additional inches; decimals and signs allowed | Decimal inches and a denominator; signs allowed |
| Main result | Decimal feet, up to 4 decimal places | Nearest reduced fraction |
| Details | Total inches, meters, normalized ft/in | Input, rounded decimal and rounding difference |
| Default | 5 ft and 8 in | 2.625 in at nearest 1/16 |
| Example | 5.6667 ft, 68 in, 1.7272 m | 2 5/8 in; zero rounding difference |
The mixed form computes total inches = 12 × feet + inches. It divides by 12 for decimal feet and multiplies by 0.0254 for meters. Entering 4 ft and 15 in gives 63 in, normalized as 5 ft 3 in.
The fraction form offers denominators 2, 4, 8, 16, 32, 64 and 128. It rounds the fractional part to the selected grid, carries a whole inch when needed and reduces the fraction. For 3.2 in at nearest 1/16, it returns 3 3/16 in, or 3.1875 in; rounded minus entered value is −0.0125 in.
Connecting the tools
If you need a ruler-grid reading for a mixed measurement, first obtain total inches, then enter that decimal value in the fraction form. Choose a denominator to match your stated precision requirement; the form does not establish a project tolerance.
Limits
The 12-inch foot and 0.0254-meter inch are exact unit relationships. The computations use finite numbers, and fraction conversion intentionally rounds. Neither adds measurement accuracy. In particular, 5 ft 8 in is not 5.8 ft, and a decimal such as 0.1 in need not land exactly on one of the offered grids.
Sources
NIST SP 811, unit definitions and Appendix B factors. The paired calculator controls and rounding described above are their current form behavior.