How to Convert Decimal Inches to Fractions
Separate the whole number from the decimal part. Multiply the decimal by the denominator you want — 16 for sixteenths, 8 for eighths, 32 for 32nds — then round to the nearest whole number.
Example: 3.625 inches. Whole = 3. Decimal = 0.625. Multiply by 16: 0.625 × 16 = 10. So 0.625 = 10/16 = 5/8. Result: 3 5/8 inches.
Common Decimals from Digital Calipers
Digital calipers read in decimal inches (or mm). When you need to transfer that measurement to a tape measure, use this converter to find the nearest standard fraction mark.
The most common caliper decimals in woodworking: 0.75 (3/4), 0.625 (5/8), 0.5 (1/2), 0.375 (3/8), 0.25 (1/4), 0.125 (1/8).