# Convert millimeters to decimeters

Enter the number of millimeters you want to convert to decimeters in the text box below. The conversion to length in decimeters will update as you type.

millimeters (mm)
1 millimeters = 0.01 decimeters

## Precise decimal and fraction answers

The conversion in decimeters rounded to six significant decimal places is 1 mm = 0.0100000 dm. The precise fraction answer is 1/100 dm.

### Decimal Precision

Conversion from one to ten decimal places

• 1 mm = 0.01 dm
• 1 mm = 0.010 dm
• 1 mm = 0.0100 dm
• 1 mm = 0.01000 dm
• 1 mm = 0.010000 dm
• 1 mm = 0.0100000 dm
• 1 mm = 0.01000000 dm
• 1 mm = 0.010000000 dm
• 1 mm = 0.0100000000 dm
• 1 mm = 0.01000000000 dm

## How many decimeters are in a millimeter?

There are 0.01 decimeters in one millimeter. A millimeter is 1.00% of a decimeter. A decimeter is 9,900% longer than one millimeter.

## Millimeters to decimeters conversion factor and formulas

Formula

The conversion factor between millimeters and decimeters is 100. This represents the ratio of millimeters per one decimeter. To calculate the value in decimeters, we can either divide by the conversion factor or multiply by its inverse.

### Division

To convert from millimeters to decimeters, divide millimeters by 100.
The formula is expressed as:
mm ÷ 100 = dm

### Multiplication

Alternatively we can multiply by the inverse conversion factor to get the same result.
The inverse of 100 is 1/100 or 0.01. To convert from millimeters to decimeters, multiply millimeters by 0.01.
The formula is expressed as:
mm × 0.01 = dm

A conversion from millimeters to decimeters are units within in the metric (SI) or SI compatible systems.

SI Unit

Within the SI (metric) system of measurement, the millimeter is officially defined as one thousandth (1/1,000) of a meter. It is commonly used when measuring very short lengths. Internationally it is spelled 'millimetre' whereas the U.S. spells it 'millimeter'. The symbol for millimeters is mm.

SI Unit

Within the SI (metric) system of measurement, the decimeter is officially defined as one tenth (1/10) of a meter. The decimeter is not widely used in everyday situations. Internationally it is spelled 'decimetre' whereas the U.S. spells it 'decimeter'. The symbol for decimeters is dm.

## Reverse this conversion

Convert from decimeters to millimeters instead.

## 1 millimeters to other length units

### Metric

• 1 mm = 1×10-6 km
• 1 mm = 0.001 m
• 1 mm = 0.01 dm
• 1 mm = 0.1 cm
• 1 mm = 1 mm
• 1 mm = 1,000 µ
• 1 mm = 1,000,000 nm

### Imperial/U.S.

• 1 mm = 6.214×10-7 mi
• 1 mm = 0.001 yd
• 1 mm = 0.003 ft
• 1 mm = 0.039 in

## References and Citations

1. International Bureau of Weights and Measures (BIPM) The International System of Units (SI)

mm dm
1 mm 0.01 dm
2 mm 0.02 dm
3 mm 0.03 dm
4 mm 0.04 dm
5 mm 0.05 dm
6 mm 0.06 dm
7 mm 0.07 dm
8 mm 0.08 dm
9 mm 0.09 dm
10 mm 0.1 dm
mm dm
20 mm 0.2 dm
30 mm 0.3 dm
40 mm 0.4 dm
50 mm 0.5 dm
60 mm 0.6 dm
70 mm 0.7 dm
80 mm 0.8 dm
90 mm 0.9 dm
100 mm 1 dm
1,000 mm 10 dm