Add, subtract, multiply, and divide feet and inches with fractions. Convert between decimal feet, total inches, and metric units.
Feet and Inches
9' 3"
With fractions
Metric
2.8194
meters
| Fraction | Decimal | mm |
|---|---|---|
| 1/16" | 0.0625 | 1.59 |
| 1/8" | 0.125 | 3.18 |
| 3/16" | 0.1875 | 4.76 |
| 1/4" | 0.25 | 6.35 |
| 5/16" | 0.3125 | 7.94 |
| 3/8" | 0.375 | 9.53 |
| 7/16" | 0.4375 | 11.11 |
| 1/2" | 0.5 | 12.70 |
| 9/16" | 0.5625 | 14.29 |
| 5/8" | 0.625 | 15.88 |
| 11/16" | 0.6875 | 17.46 |
| 3/4" | 0.75 | 19.05 |
| 13/16" | 0.8125 | 20.64 |
| 7/8" | 0.875 | 22.23 |
| 15/16" | 0.9375 | 23.81 |
| 1" | 1.0 | 25.40 |
To add feet and inches: First add the feet, then add the inches. If inches exceed 12, convert to feet. Example: 5'6" + 3'9" = 8'15" = 9'3" (15" - 12" = 3", carry 1 foot). To multiply: Convert to decimal feet or total inches first, multiply, then convert back. Example: 4'6" x 3 = 4.5 x 3 = 13.5 feet = 13'6".
Add the feet together, then add the inches together. If the inches total 12 or more, subtract 12 and add 1 to the feet. Example: 5'6" + 3'9" = 8'15". Since 15" > 12", subtract 12 (15-12=3) and add 1 foot. Result: 9'3".
Subtract inches first. If you need to borrow, take 1 foot (12 inches) from the feet. Example: 10'4" - 3'8". You can't subtract 8 from 4, so borrow: 9'16" - 3'8" = 6'8".
Convert to decimal feet first (divide inches by 12 and add to feet), multiply, then convert back. Example: 4'6" x 3 = 4.5 ft x 3 = 13.5 ft = 13'6". Alternative: convert to inches (54"), multiply (162"), divide by 12 (13.5').
Convert to total inches, divide, then convert back to feet and inches. Example: 12'3" / 3 = 147" / 3 = 49" = 4'1".
The whole number is feet. Multiply the decimal by 12 to get inches. Example: 5.75 feet = 5 feet + (0.75 x 12) inches = 5'9".
Common fractions: 1/16" (finest typical), 1/8", 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8", 15/16". On a tape measure, 1/16" marks are smallest, 1/8" slightly longer, 1/4" longer still, 1/2" second longest, inch marks longest.
Standard lumber lengths: 8', 10', 12', 14', 16', 20'. Nominal vs actual: 2x4 is actually 1.5" x 3.5", 2x6 is 1.5" x 5.5", 2x8 is 1.5" x 7.25". Sheet goods: 4' x 8' (plywood, drywall, OSB).
First convert to total inches. Multiply inches by 2.54 to get centimeters, or by 25.4 for millimeters. Example: 5'6" = 66" = 66 x 2.54 = 167.64 cm = 1.6764 m.
Feet and Inches
9' 3"
With fractions
Metric
2.8194
meters