How length conversion works
Length units use fixed relationships: 1 cm = 10 mm, 1 m = 100 cm, 1 inch = 25.4 mm, 1 foot = 12 inches and 1 yard = 3 feet. 1Ruler converts through an exact meter-based factor so the same calculation works in both directions.
Example conversion
Enter 125 cm and convert it to inches to get about 49.2126 in. The result panel also shows the same length in the other supported units so you can compare values without repeating the calculation.
Measure, convert and copy
The on-screen ruler and the converter are connected. After you measure a span with 1Ruler, its millimeter, centimeter, meter, inch and foot equivalents appear directly below the ruler. You can copy the combined result or open it in this converter for another unit pair.
When calibration matters
Typed unit conversions use defined conversion factors and do not require screen calibration. Measurements taken from the on-screen ruler depend on your display scale, so calibrate the ruler when you need a closer physical-size result.