Inches to Kilometers Converter

About the in to km calculation

One inch is exactly 0.0000254 kilometers, so converting between them is a single multiplication. Enter any value above and the result updates as you type. Still standard for screen sizes, pipe diameters and tyre rims worldwide. The standard road-distance unit in most of the world.

Formula

km = in × 0.0000254

1 in = 0.0000254 km
1 km = 39,370.08 in

Worked example

To convert 12 in, multiply by 0.0000254: 12 × 0.0000254 = 0.0003048 km.

Frequently asked questions

How many kilometers are in a inch?

There are 0.0000254 kilometers in one inch. To convert any amount, multiply the number of inches by 0.0000254.

How do I convert kilometers back to inches?

Divide instead of multiplying, or equivalently multiply by 39,370.08. One kilometer is 39,370.08 inches.

Is this conversion exact?

Yes. Since the international agreement of 1959, the relationship between inches and kilometers is defined exactly rather than measured, so the only rounding here is in how many decimal places we show.

Where is each of these units used?

Inches: still standard for screen sizes, pipe diameters and tyre rims worldwide. Kilometers: the standard road-distance unit in most of the world.

Sources

• NIST Special Publication 811 — Guide for the Use of the International System of Units