Molar to Micromolar Converter

µM

Common Conversions

M	µM
1e-7	0.1
0.000001	1
0.00001	10
0.0001	100
0.001	1000
0.01	10000
0.1	100000
0.5	500000
1	1000000
2	2000000
5	5000000

Why this conversion matters in chemistry

Stocks live in molar; assays live in micromolar. The conversion bridges six orders of magnitude in a single step. A 10⁻⁷ M working concentration in a kinase inhibition assay is 0.1 µM — the kind of value that anchors a dose-response curve from a 100 µM top-dose down through three-fold serial dilutions. Multiplying by 10⁶ is the bookkeeping that lets a stock dilution scheme line up with the µM concentrations a screening hit gets reported in. Getting the prefix right is what separates a confident potency comparison from one off by three orders of magnitude.

Formula

µM = M × 1000000

Worked Examples

0.001 M = 1000 µM

One millimolar in µM — the bridge step between adjacent prefixes most calculations actually take.

0.000001 M = 1 µM

One micromolar — a respectable potency for an early-discovery inhibitor.

0.0001 M = 100 µM

A typical screening-assay starting concentration, the top of a dose-response titration.

1 M = 1000000 µM

One molar in µM — useful only as a sanity check on the million-fold scale separation.

Frequently Asked Questions

How do I convert M to µM?

Multiply by 1,000,000. The relationship is exact, so 0.0001 M is precisely 100 µM with no rounding.

What's the prefix path?

M → mM is ×1000, and mM → µM is another ×1000. Doing it as two mental steps is often easier than reaching for the full ×10⁶ factor at once.

When are micromolar concentrations used?

Pharmacology (IC50 values for inhibitors), enzyme kinetics (substrate concentrations near Km), fluorescence spectroscopy, and most cell-biology dose-response assays. Anywhere the chemistry of interest happens at low concentration but not so low that nM is the natural unit.

How do I prepare a 10 µM solution?

Prepare a 10 mM stock first, then dilute 1:1000. So 10 µL of 10 mM stock added to 10 mL total volume gives 10 µM. Single-step dilution from a high-molarity stock to a µM working concentration is rarely accurate enough to trust.