How do you convert inches to decimal feet?
Divide the inches by 12 to get decimal feet — there are 12 inches in a foot. So 6 inches = 0.5 ft, 3 inches = 0.25 ft, and 9 inches = 0.75 ft. For a mixed measurement, convert the inches and add: 8 ft 6 in = 8 + (6 ÷ 12) = 8.5 ft.
Source: Unit conversion (12 in = 1 ft) · Verify against your AHJ and the adopted code edition.
There are 12 inches in a foot, so decimal feet = inches ÷ 12.
Common values worth memorizing:
| Inches | Decimal feet |
|---|---|
| 1 in | 0.083 ft |
| 3 in | 0.25 ft |
| 6 in | 0.5 ft |
| 8 in | 0.667 ft |
| 9 in | 0.75 ft |
For a mixed measurement, convert just the inches and add the whole feet: 8 ft 6 in = 8 + (6 ÷ 12) = 8.5 ft. Going the other way, multiply the decimal part by 12: 8.5 ft = 8 ft + (0.5 × 12) = 8 ft 6 in.
Decimal feet make areas and volumes easy — you can multiply lengths directly (square footage, concrete yards) without juggling feet-and-inches.
Work it out: the feet-inch-fraction converter
parses messy input like 8' 6" or 102" and gives you decimal feet, decimal
inches, and metric all at once.