Millimeters to centimeters converter
Convertersconversion pair
Convert millimeters to centimeters instantly: 10 mm make 1 cm. Rulers, rain gauges and small measurements, with the exact math and a copy button.
10 mm to a centimeter — the metric system's one genuinely easy step.
work surface
Math, not advice — results are indicative. Read the disclaimer.
pro tips
Divide by 10. It's the one conversion you can do mid-sentence without breaking eye contact.
10 mm is exactly 1 cm — the metric system's most honest shortcut.
A "1.0 mm" pen puts down 0.1 cm of ink per stroke, which sounds far less decisive.
what it does
Moving from millimeters to centimeters is the metric system's easiest trick: divide by 10. That's the entire method — a decimal point sliding one place left, no memory aids, no conversion table taped to the fridge.
You meet it when a ruler marks both mm and cm and quietly expects you to translate, when rainfall is reported in millimetres but compared in centimetres, when jewellery and screws are measured in mm while clothes are sized in cm, and every school ruler that starts the argument about whether 30 mm is "3 cm or 30".
The shortcut is genuinely free here: 25 mm is 2.5 cm, 100 mm is 10 cm, and 1,000 mm is 100 cm, which is also a metre, which is also the entire point of the system. Every step is a power of ten wearing a different label.
Type any millimetre number and the widget answers in centimetres instantly. Click the result to copy it, and swap when a measurement runs the other way and someone hands you centimetres to grow back into millimetres.
quick answers
How many mm are in a cm?
Exactly 10. No caveats, no history of units, just a clean power of ten.
Is 100 mm equal to 1 cm?
No — it's 10 cm. Mixing up the zero is the classic slip; count the places.
Why use mm instead of cm at all?
Precision and habit: engineers and makers default to mm so nothing lands in a decimal they didn't choose.