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cm to mm Conversion

Convert centimeters into millimeters (and back) while keeping meter and inch references handy.

Formula shown0 inputs definedUpdated Nov 2025By CalcuTotal TeamFree, no sign-up

Quick Summary

Use this when you need:

Convert PCB trace specs from cm to mm
Check sewing measurements that mix mm and cm
Offer inch context when sharing metric-only dims

You’ll get:Length

How this is calculated

Formula:

length_target = length_source

In plain language:

Centimeters multiply by ten to reach millimeters; all inputs normalize to meters first to keep precision across units.

The formula is always visible so you can verify the math and explain your numbers to anyone who asks.

What these terms mean

Length

Length used in the calculation.

When to use this calculator

Convert PCB trace specs from cm to mm
Check sewing measurements that mix mm and cm
Offer inch context when sharing metric-only dims

Last updated: November 24, 2025

Centimeters to millimeters explained

Millimeters are handy for fine tolerances in fabrication, printing, and electronics. Converting from centimeters is a single factor of 10, so you can move the decimal one place for quick checks.

How the conversion works

Metric prefixes define the ratio: $1\\ \\text{cm} = 10\\ \\text{mm}$ because $1\\ \\text{m} = 1000\\ \\text{mm}$ and $1\\ \\text{m} = 100\\ \\text{cm}$ . citeturn0search13

Formulas:

$\\text{mm} = \\text{cm} \\times 10$

\\text{cm} = \\text{mm} \\div 10

Units and conversions

Unit	Symbol	Relation
millimeter	mm	$0.001\\ \\text{m}$
centimeter	cm	$0.01\\ \\text{m}$
meter	m	base unit
inch	in	$25.4\\ \\text{mm}$ (exact) citeturn2search12

Worked examples

PCB trace width
0.35 cm copper trace → $0.35 \\times 10 = 3.5\\ \\text{mm}$ .
120 mm hinge spacing in cm
$120 \\div 10 = 12\\ \\text{cm}$ for a drawing annotated in centimeters.
Reverse tiny clearance
1.2 mm shim → $1.2 \\div 10 = 0.12\\ \\text{cm}$ .

Tips and pitfalls

For mechanical fits, keep at least one decimal millimeter (0.1 mm).
Convert fractions of an inch to mm before rounding (e.g., $\\tfrac{1}{8}$ in = 3.175 mm).
Keep base calculations in meters to avoid cumulative rounding.

References and further reading

Orders of magnitude (length) — Wikipedia citeturn0search13
International inch definition — Wikipedia citeturn2search12

Frequently Asked Questions

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Calculator info

Version:: v1.0.0
Last reviewed:: Nov 24, 2025
Sensitivity:: low
References:: 1

Last updated: November 24, 2025

Centimeters to millimeters explained

Millimeters are handy for fine tolerances in fabrication, printing, and electronics. Converting from centimeters is a single factor of 10, so you can move the decimal one place for quick checks.

How the conversion works

Metric prefixes define the ratio: $1\\ \\text{cm} = 10\\ \\text{mm}$ because $1\\ \\text{m} = 1000\\ \\text{mm}$ and $1\\ \\text{m} = 100\\ \\text{cm}$ . citeturn0search13

Formulas:

$\\text{mm} = \\text{cm} \\times 10$

\\text{cm} = \\text{mm} \\div 10

Units and conversions

Unit	Symbol	Relation
millimeter	mm	$0.001\\ \\text{m}$
centimeter	cm	$0.01\\ \\text{m}$
meter	m	base unit
inch	in	$25.4\\ \\text{mm}$ (exact) citeturn2search12

Worked examples

PCB trace width
0.35 cm copper trace → $0.35 \\times 10 = 3.5\\ \\text{mm}$ .
120 mm hinge spacing in cm
$120 \\div 10 = 12\\ \\text{cm}$ for a drawing annotated in centimeters.
Reverse tiny clearance
1.2 mm shim → $1.2 \\div 10 = 0.12\\ \\text{cm}$ .

Tips and pitfalls

For mechanical fits, keep at least one decimal millimeter (0.1 mm).
Convert fractions of an inch to mm before rounding (e.g., $\\tfrac{1}{8}$ in = 3.175 mm).
Keep base calculations in meters to avoid cumulative rounding.

References and further reading

Orders of magnitude (length) — Wikipedia citeturn0search13
International inch definition — Wikipedia citeturn2search12

Quick Summary

Calculator Tool

How this is calculated

What these terms mean

Length

When to use this calculator

Centimeters to millimeters explained

How the conversion works

Units and conversions

Worked examples

Tips and pitfalls

References and further reading

Frequently Asked Questions

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Calculator info

Centimeters to millimeters explained

How the conversion works

Units and conversions

Worked examples

Tips and pitfalls

References and further reading

Frequently Asked Questions

Related Calculators

cm to in Converter

cm to km Conversion

cm to m Converter

Inches to Yards Converter

Acreage Calculator

Angstrom to nm converter

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