About

In a globalized manufacturing environment, the friction between Metric (cm) and Imperial (inches) systems creates constant challenges for DIY enthusiasts, carpenters, and machinists. While centimeters offer decimal precision, the Imperial system - standard in the US and UK construction industries - relies heavily on fractions. A generic calculator returning 5.3937 inches is useless to a carpenter holding a tape measure marked in 16ths.

This tool addresses the practical reality of measurement. It provides the standard decimal conversion for engineering accuracy and a "tape measure friendly" fractional approximation. This dual output ensures that whether you are configuring 3D printer settings or cutting lumber for a frame, you have the exact format required for the task.

Formulas

The inch is legally defined as exactly 2.54 centimeters. The conversion logic divides the metric input by this constant.

L_in = L_cm2.54

To calculate the fraction, the decimal part is multiplied by the desired denominator (e.g., 32 or 64), rounded to the nearest integer, and then reduced to its simplest form using the Greatest Common Divisor (GCD).

Reference Data

Centimeters (cm)	Decimal Inches (in)	Fractional Inch (Approx)
0.158	0.0625	116
0.317	0.125	18
0.635	0.25	14
1.27	0.50	12
2.54	1.00	1
5.08	2.00	2
10.00	3.937	3 1516
30.48	12.00	12 (1 Foot)

Frequently Asked Questions

The fractional output finds the nearest 1/64th of an inch. While sufficient for carpentry and general fabrication, it is an approximation. Always use the decimal value for high-tolerance engineering tasks.

In 1959, the International Yard and Pound Agreement standardized the inch as exactly 25.4 millimeters (2.54 cm). Before this, slight variations existed between British and American inches.

Yes. Screen sizes are measured diagonally in inches. If you measure a screen width in cm, you can convert it here, but remember screen "size" refers to the diagonal, not width or height.