µm to mm Converter
Type a value in micrometers to see it in millimeters as you type, with the exact formula and a reference chart.
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- Centimeters
- 0.025 cm
How this was calculated
- 1 millimeter = 1,000 micrometers
- 250 ÷ 1,000 = 0.25 mm
| µm | mm |
|---|---|
| 1 µm | 0.001 mm |
| 5 µm | 0.005 mm |
| 10 µm | 0.01 mm |
| 25 µm | 0.025 mm |
| 50 µm | 0.05 mm |
| 75 µm | 0.075 mm |
| 100 µm | 0.1 mm |
| 250 µm | 0.25 mm |
| 500 µm | 0.5 mm |
| 750 µm | 0.75 mm |
| 1,000 µm | 1 mm |
| 2,000 µm | 2 mm |
| 5,000 µm | 5 mm |
| mm | µm |
|---|---|
| 0.001 mm | 1 µm |
| 0.01 mm | 10 µm |
| 0.05 mm | 50 µm |
| 0.1 mm | 100 µm |
| 0.25 mm | 250 µm |
| 0.5 mm | 500 µm |
| 1 mm | 1,000 µm |
| 2 mm | 2,000 µm |
| 5 mm | 5,000 µm |
| 10 mm | 10,000 µm |
| 25 mm | 25,000 µm |
| 50 mm | 50,000 µm |
How to convert micrometers to millimeters
1 micrometer = 0.001 millimeters. To convert micrometers to millimeters, divide by 1,000 (or multiply by 0.001). A micrometer (µm, also called a micron) is one millionth of a meter, one thousandth of a millimeter. A millimeter is one thousandth of a meter.
Worked examples
- 50 micrometers = 0.05 mm (50 ÷ 1,000)
- 250 micrometers = 0.25 mm (250 ÷ 1,000)
- 1,000 micrometers = 1 mm (1,000 ÷ 1,000)
Where this conversion comes up
Micrometers are used for dust and pollen particles, filter ratings, bacteria and coating thickness; millimeters for screw and drill sizes, rainfall, paper and phone dimensions. Filter ratings, particle sizes, coating thickness and tolerances are quoted in micrometers (µm, often typed "um"), while drawings use millimeters. 1,000 µm is exactly 1 mm, so a 50 µm hair-thin coating is 0.05 mm.
Quick estimate
Divide by 1,000: 250 µm = 0.25 mm.
Common mistakes
- Multiplying instead of dividing. A millimeter is larger than a micrometer, so the number of millimeters must come out smaller: 50 micrometers = 0.05 mm.
Going the other way? Use the mm to µm converter. Related length converters: mm to inches, inches to mm, inches to feet, feet to inches, meters to feet, feet to meters.
Frequently asked questions
How do you convert micrometers to millimeters?
Multiply the micrometers by 0.001 (or divide by 1,000). For example, 250 micrometers is 0.25 millimeters.
How many millimeters are in one micrometer?
One micrometer is 0.001 millimeters. A micrometer (µm, also called a micron) is one millionth of a meter, one thousandth of a millimeter.
What is 1,000 micrometers in millimeters?
1,000 micrometers is 1 millimeters.
Is there a quick way to estimate micrometers to millimeters?
Divide by 1,000: 250 µm = 0.25 mm.