The centiinch is a metric unit of length. One centiinch equals 0.000254 meters, so every conversion on this page starts from that single number. Metric units are built from the meter with a prefix, so moving between them only ever means shifting the decimal point.

Because the whole system works in powers of ten, you can convert centiinch to any other metric unit without memorizing odd numbers. The table further down does the arithmetic for the values people look up most.

In writing, the centiinch is usually shortened to "cin". One centiinch is 0.000254 meters, and that ratio is what every figure on this page is built from.