Convert Millimeter to Decimeter

Convert millimeters to decimeters by entering a value below.

1 mm (millimeters) = 0.01 dm (decimeters)

How to Convert Millimeters to Decimeters

The millimeter and decimeter are both units of length. By definition, 1 decimeter equals exactly 100 millimeters. This means to convert millimeters to decimeters, you divide by 100.

Formula

decimeters = millimeters ÷ 100

Step-by-Step Example

Convert 5 mm to decimeters:

1
Convert 5 mm to decimeters

We need to convert millimeters to decimeters

2
Apply the formula

Since 1 dm = 100 mm, divide by 100

5 ÷ 100 = 0.05

Answer

5 mm = 0.05 dm

Millimeter to Decimeter Conversion Table

Quick reference table for common millimeter to decimeter conversions. Click any value for detailed calculation.

Millimeters (mm) Decimeters (dm)
1 mm 0.01 dm
2 mm 0.02 dm
5 mm 0.05 dm
10 mm 0.1 dm
15 mm 0.15 dm
20 mm 0.2 dm
25 mm 0.25 dm
50 mm 0.5 dm
100 mm 1 dm

About These Units

Millimeter (mm)

A millimeter (mm) is a metric unit of length equal to 1/1000 of a meter or 0.03937 inches. Millimeters are essential for precision measurements in engineering, manufacturing, medical imaging, and rainfall measurements. There are 25.4 mm in one inch.

Decimeter (dm)

A decimeter (dm) is a metric unit of length equal to 1/10 of a meter, 10 centimeters, or approximately 3.94 inches. Decimeters are commonly used in Europe for measuring furniture dimensions, fabric lengths, and in educational contexts.

Frequently Asked Questions

How do I convert millimeters to decimeters?

To convert millimeters to decimeters, divide the value by 100. For example, 10 mm = 0.1 dm.

How many decimeters are in 1 millimeter?

1 millimeter equals 0.01 decimeters.

What is the formula for millimeters to decimeters?

The formula is: dm = mm ÷ 100.