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Inches to Fraction Calculator

Convert decimal inch measurements to fractions for woodworking, machining, and construction. Enter a decimal value and choose your precision, and the calculator gives you the closest standard fraction.

Tape measures and drill bits are labeled in fractions of an inch, but digital calipers and CAD software output decimals. This calculator bridges the gap by converting any decimal inch value to the nearest standard fraction.

How it works: The calculator multiplies the decimal portion by your chosen denominator, rounds to the nearest whole number, and simplifies the resulting fraction.

Common Decimal-to-Fraction Conversions:

Decimal Fraction mm
0.0625 1/16" 1.588
0.125 1/8" 3.175
0.1875 3/16" 4.763
0.25 1/4" 6.350
0.3125 5/16" 7.938
0.375 3/8" 9.525
0.4375 7/16" 11.113
0.5 1/2" 12.700
0.5625 9/16" 14.288
0.625 5/8" 15.875
0.6875 11/16" 17.463
0.75 3/4" 19.050
0.8125 13/16" 20.638
0.875 7/8" 22.225
0.9375 15/16" 23.813

Choosing precision: For general woodworking, 1/16" is usually fine. Machining typically needs 1/32" or 1/64". The rounding error output shows how far off the fraction is from the exact decimal, so you can judge if the precision is good enough for your project.

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