How do I convert mm to cm?

Use the formula shown above or enter a value to see mm converted to cm instantly.

What is the formula for mm to cm?

The converter calculates cm by applying the category-specific conversion factor for Length.

When should I use mm vs cm?

mm and cm are both part of the Length category; pick the unit that matches your measurement context (e.g., scale, region, or industry standard).

Length Converter & Reference

Convert mm to cm

Use the live converter below to translate between Millimeter (mm) and Centimeter (cm). Scroll further for quick examples, formula tips, and related units.

Formula insight: Most unit conversions use a simple multiplication or division by a conversion factor. The calculator shows the exact formula used.

Convert

mm → cm

Millimeter

Centimeter

0.1

Rounded result (4 decimals max)

Formula

1 mm = 0.1 cm

Conversion sourcesTap or click to view references

The International System of Units (SI) — NIST Special Publication 330
National Institute of Standards and Technology (NIST). The SI Brochure (SP 330) is the definitive English edition of the BIPM SI tables. NIST’s edition lists the official constants and conversion factors tying inch-pound units to SI, which SwapUnits applies for length, mass, temperature, pressure, volume, and related conversions. See /standards/nist-si-tenfold for the complete decimal multiple/submultiple table. View source · View SI table

Results update as you type. Swap the direction to convert back from cm to mm.

Back to main converter

mm to cm quick table

Multiply any row by the same factor to scale results. Use the converter above to enter exact values with your own units.

Millimeter (mm)	Centimeter (cm)
0.25 mm	0.025 cm
0.5 mm	0.05 cm
1 mm	0.1 cm
2 mm	0.2 cm
5 mm	0.5 cm
10 mm	1 cm
25 mm	2.5 cm
100 mm	10 cm

cm back to mm

Keep the reciprocal handy when double-checking calculations or undoing a conversion.

Centimeter (cm)	Millimeter (mm)
0.25 cm	2.5 mm
0.5 cm	5 mm
1 cm	10 mm
2 cm	20 mm
5 cm	50 mm
10 cm	100 mm
25 cm	250 mm
100 cm	1,000 mm

Explore more length converter & reference

mm → nm

Convert into Nanometer without leaving SwapUnits.

mm → µm

Convert into Micrometer without leaving SwapUnits.

mm → in

Convert into Inch without leaving SwapUnits.

mm → ft

Convert into Foot without leaving SwapUnits.

mm → yd

Convert into Yard without leaving SwapUnits.

mm → m

Convert into Meter without leaving SwapUnits.

Compare all length converter & reference

View the full unit roster, charts, and tips for Length Converter & Reference conversions.

Open category guide