1 inches to mm

Updated July 2026

1 inches equals 25.4 mm

1 inch = 25.4 mm. That is how many millimeters there are in 1 inch. Enter any value in the free length converter to convert inches to millimeters (and every other unit) instantly — it runs privately in your browser.

Formula: Multiply by 25.4 — 1 inch = 25.4 millimeters. So 1 × 25.4 = 25.4 mm.

inches to mm conversion table

inch (in)millimeters (mm)
0.25 in6.35 mm
0.5 in12.7 mm
0.75 in19.05 mm
1 in25.4 mm
1.25 in31.75 mm
1.5 in38.1 mm
1.75 in44.45 mm

Frequently asked questions

How many millimeters is 1 inch?
1 inch is 25.4 millimeters. Multiply inches by 25.4 to get mm.
What is 1 inches to mm?
1 inch = 25.4 mm.
How do you convert inches to mm?
Multiply by 25.4 — 1 inch = 25.4 millimeters. So 1 × 25.4 = 25.4 mm.

Other inches to mm conversions

Convert 1 inches to other units