Micromole is 0.000001 mole units.
Micromoles to Millimoles Converter — umol to mmol
Convert Micromole (umol) to Millimole (mmol) using the exact conversion factor (1 micromole = 0.001 millimole). See the formula, worked examples, and conversion table.
Micromoles to Millimoles converter
Converter
Chemistry Converter
Convert concentration, molarity, amount, and laboratory scientific units by compatible family.
Context values
Some unit families need one extra value for a physically accurate result.
Millimole is 0.001 mole units.
Result = input x 1e-6 / 0.001.
Amount units are compatible.
Reserved above the conversion cards and below the converter.
About Converting Micromoles to Millimoles
Micromole and Millimole both measure mass concentration — how much of a substance is dissolved or dispersed in a given volume — a core calculation for preparing lab solutions, checking water quality against a regulatory limit, or formulating a pharmaceutical dose. Specifically: Micromole is 0.000001 mole units, and millimole is 0.001 mole units.
Formula
millimoles = micromoles × 0.001
This factor comes from each unit's defined relationship to the category's base unit: 1 micromole equals 0.000001 base units, and 1 millimole equals 0.001 base units, so dividing one by the other gives the direct micromole-to-millimole factor of 0.001.
Simple example
1 umol × 0.001 = 0.001 mmol
1 micromole = 0.001 millimoles.
Real-world example
100 umol × 0.001 = 0.1 mmol
100 micromoles = 0.1 millimoles.
Conversion table
| Micromole (umol) | Millimole (mmol) |
|---|---|
| 0.001 umol | 0.000001 mmol |
| 0.01 umol | 0.00001 mmol |
| 0.1 umol | 0.0001 mmol |
| 1 umol | 0.001 mmol |
| 10 umol | 0.01 mmol |
| 100 umol | 0.1 mmol |
Reverse conversion: Millimole to Micromole
0.001 mmol × 1000 = 1 umol
0.001 millimoles = 1 micromole.
micromoles = millimoles × 1000
For a page dedicated to this direction, see Millimole to Micromole.
Understanding the Micromole (umol)
Micromole is 0.000001 mole units.
Understanding the Millimole (mmol)
Millimole is 0.001 mole units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many millimoles are in 1 micromole?
1 micromole equals 0.001 millimoles, using the exact defined conversion factor rather than an estimate.
How do I convert micromole to millimole?
Multiply the micromole value by 0.001. The converter above does this instantly to whatever precision you set.
How do I convert millimole back to micromole?
Use the reverse factor: 1 millimole equals 1,000 micromoles. You can also use the swap control in the converter above to flip the direction instantly.
What is a micromole?
Micromole (umol) is a unit of chemistry.
What is a millimole?
Millimole (mmol) is a unit of chemistry.
Is the micromole to millimole conversion exact?
Yes. Both micromole and millimole are defined by fixed standards rather than physical artifacts, so the factor of 0.001 used above is exact to as many digits as you choose to display.
What's the difference between mass concentration and molarity?
Mass concentration expresses how much mass of a substance is present per unit volume (for example, grams per liter). Molarity expresses the amount in moles per liter instead, which accounts for the substance's molecular weight. This category converts mass-concentration units.