How many micrometers are in 1 millimeter?

1 mm equals 1000 µm. This is an exact conversion factor defined by NIST.

How do I convert millimeters to micrometers?

Multiply the value in mm by the conversion factor. For example, 10 mm = 10000 µm. Use our calculator above for instant results.

Is the millimeters to micrometers conversion exact?

Yes, this conversion is mathematically exact based on the international definition of these units (NIST SP 811).

Can I convert millimeters to micrometers offline?

Yes! OmniConvert runs entirely in your browser — no internet connection needed after the page loads. Your data never leaves your device, ensuring complete privacy.

What is the difference between millimeters and micrometers?

Millimeters (mm) and Micrometers (µm) are both units of length but belong to different measurement systems. 1 mm = 1000 µm. Use the converter above to switch between them instantly.

Millimeters to Micrometers (mm → µm) — Free Online Converter

mm → µm Reference Table

mm	µm
0.001 mm	1 µm
0.002 mm	2 µm
0.003 mm	3 µm
0.004 mm	4 µm
0.005 mm	5 µm
0.006 mm	6 µm
0.007 mm	7 µm
0.008 mm	8 µm
0.009 mm	9 µm
0.01 mm	10 µm
0.02 mm	20 µm
0.03 mm	30 µm
0.04 mm	40 µm
0.05 mm	50 µm
0.06 mm	60 µm
0.07 mm	70 µm
0.08 mm	80 µm
0.09 mm	90 µm
0.1 mm	100 µm
0.2 mm	200 µm
0.3 mm	300 µm
0.4 mm	400 µm
0.5 mm	500 µm
0.6 mm	600 µm
0.7 mm	700 µm
0.8 mm	800 µm
0.9 mm	900 µm
1 mm	1000 µm
1.5 mm	1500 µm
2 mm	2000 µm
2.5 mm	2500 µm
3 mm	3000 µm
3.5 mm	3500 µm
4 mm	4000 µm
4.5 mm	4500 µm
5 mm	5000 µm
5.5 mm	5500 µm
6 mm	6000 µm
6.5 mm	6500 µm
7 mm	7000 µm
7.5 mm	7500 µm
8 mm	8000 µm
8.5 mm	8500 µm
9 mm	9000 µm
9.5 mm	9500 µm
10 mm	10000 µm
11 mm	11000 µm
12 mm	12000 µm
13 mm	13000 µm
14 mm	14000 µm
15 mm	15000 µm
16 mm	16000 µm
17 mm	17000 µm
18 mm	18000 µm
19 mm	19000 µm
20 mm	20000 µm
25 mm	25000 µm
30 mm	30000 µm
35 mm	35000 µm
40 mm	40000 µm
45 mm	45000 µm
50 mm	50000 µm
55 mm	55000 µm
60 mm	60000 µm
65 mm	65000 µm
70 mm	70000 µm
75 mm	75000 µm
80 mm	80000 µm
85 mm	85000 µm
90 mm	90000 µm
95 mm	95000 µm
100 mm	100000 µm
120 mm	120000 µm
125 mm	125000 µm
130 mm	130000 µm
140 mm	140000 µm
150 mm	150000 µm
160 mm	160000 µm
175 mm	175000 µm
180 mm	180000 µm
200 mm	200000 µm
225 mm	225000 µm
250 mm	250000 µm
275 mm	275000 µm
300 mm	300000 µm
350 mm	350000 µm
400 mm	400000 µm
450 mm	450000 µm
500 mm	500000 µm
600 mm	600000 µm
700 mm	700000 µm
750 mm	750000 µm
800 mm	800000 µm
900 mm	900000 µm
1000 mm	1000000 µm
1200 mm	1200000 µm
1250 mm	1250000 µm
1500 mm	1500000 µm
1750 mm	1750000 µm
2000 mm	2000000 µm
2500 mm	2500000 µm
3000 mm	3000000 µm
4000 mm	4000000 µm
4500 mm	4500000 µm
5000 mm	5000000 µm
6000 mm	6000000 µm
7000 mm	7000000 µm
7500 mm	7500000 µm
8000 mm	8000000 µm
9000 mm	9000000 µm
10000 mm	10000000 µm
15000 mm	15000000 µm
20000 mm	20000000 µm
25000 mm	25000000 µm
50000 mm	50000000 µm
75000 mm	75000000 µm
100000 mm	100000000 µm

Values based on NIST SP 811 conversion factors

Why Convert Millimeters to Micrometers?

Converting between millimeters (mm) and micrometers (µm) is one of the most common length conversions. Whether for engineering, cooking, travel, or science, knowing how to quickly convert mm to µm saves time and prevents errors.

Length conversions between mm and µm are fundamental in construction, manufacturing, and international trade. Architects rely on precise conversions when adapting building plans between metric and imperial standards — a 1% error on a 30-meter wall translates to 30 cm of misalignment. Travelers frequently convert between kilometers and miles for road trips, while online shoppers need length conversions to verify clothing sizes, furniture dimensions, and screen diagonals across international retailers. In athletics, track distances (100m, 1500m, marathon) must be precisely converted for record comparisons across different measurement traditions.

How to Convert Millimeters to Micrometers

To convert millimeters to micrometers, use the following formula:

µm = mm × 1000

Example: 1 mm = 1000 µm

For example, 5 mm = 5000 µm, 10 mm = 10000 µm, and 100 mm = 100000 µm. For larger values, 1000 mm = 1000000 µm. Conversely, 1 µm = 0.001 mm. Our calculator above performs this conversion instantly with full precision — no rounding errors.

Common Mistakes to Avoid

Confusing similar units: confusing nautical miles with regular miles, or yards with meters.
Decimal errors: moving the decimal point the wrong way (e.g., 100 cm = 1 m, not 10 m).
Approximation: assuming an inch is exactly 2.5 cm (it's 2.54 cm).

Pro Tips

Use 'approx' for mental math: 1 km is roughly 0.6 miles (or 2/3 for quick estimates).
Visualize: A meter is about a guitar length; an inch is a thumb width.
Ruler check: Most rulers show cm and inches together—great for quick checks.

What is a Millimeter?

The millimeter (mm) is a metric unit of length equal to one-thousandth of a meter (0.001 m). It is a standard unit in the International System of Units (SI).

Millimeters are used for precision engineering, manufacturing dimensions, rainfall measurement, and paper sizes (ISO 216). It represents small scale accuracy.

What is a Micrometer?

A unit of length in the metric system equal to one millionth of a meter (1×10⁻⁶ m). Also known as a micron.

Widely used in microscopy, biology for measuring cell sizes, and in manufacturing for specifying tolerances.

Millimeters → Micrometers

Millimeters to Micrometers Formula