Gauge Conversion Calculator — 10cm, 4-inch & Per-Inch

10cm is 3.937 inches, so it is very close to 4 inches but not exactly the same. A gauge of 20 stitches per 10cm equals approximately 20.3 stitches per 4 inches. For most projects this difference is negligible, but for large garments it can add up to a centimetre or more in total width.

US patterns traditionally use 4 inches as the gauge standard, while UK and European patterns use 10cm. Modern patterns increasingly use 10cm as the international standard. Always check which measurement system your pattern uses before comparing your swatch gauge.

Use a ruler or gauge tool rather than a tape measure for accuracy. Place pins at exact measurement points and count the stitches between pins. Count half-stitches at the edges. Measure in the centre of your swatch, away from the edges which may be distorted by selvedge stitches.