Micromolar to Picomolar Converter
Common Conversions
| µM | pM |
|---|---|
| 0.000001 | 1 |
| 0.00001 | 10 |
| 0.0001 | 100 |
| 0.001 | 1000 |
| 0.01 | 10000 |
| 0.1 | 100000 |
| 1 | 1000000 |
| 5 | 5000000 |
| 10 | 10000000 |
| 100 | 100000000 |
| 1000 | 1000000000 |
| 10000 | 10000000000 |
Why this conversion matters in chemistry
Micromolar and picomolar sit a factor of a million apart, which means this conversion almost never gets used in one calculation — it shows up when two different stages of a project have to be compared. An early screening hit at 2 µM IC50 looks respectable; an optimized candidate at 200 pM is roughly ten thousand times more potent, and writing both in the same unit makes that gap legible. The arithmetic is trivial (µM × 10⁶ = pM), but the mental move is non-trivial: most of the interesting chemistry happens in the middle of the scale, and the ends exist mainly so you can talk sensibly about very tight binding or very dilute detection.
Formula
Where the factor comes from
Prefix exponents subtract. Micro is 10⁻⁶, pico is 10⁻¹², and (−6) − (−12) = 6, so one micromolar holds 10⁶ picomolar. Both symbols decorate the same underlying unit, mol/L, which cancels out of the ratio and carries the solute's identity away with it. The factor is a stipulation — the SI fixes what micro and pico mean — so no experiment will ever revise it. It pairs usefully with another exact number that is far less obvious: since 2019 the Avogadro constant has been fixed at 6.02214076 × 10²³ mol⁻¹, which puts about 6 × 10⁷ molecules in a 100 µL well at 1 pM. Six decades of dilution still leave tens of millions of particles in the well.
Precision and significant figures
Six decades is far enough that decimal notation stops helping. 0.00024 µM and 240 pM are the same value, but only the second puts the significant digits near the decimal point, and the first invites a miscounted zero. Leading zeros are placeholders, not figures: both forms carry two. The factor contributes no uncertainty of its own, so whatever the micromolar entry justified survives unchanged. Be skeptical even of two figures arriving from the picomolar end. Potencies down there come from fits near the bottom of a dose–response curve, where the confidence interval on the fitted value routinely spans a factor of two or three, and a tidy 240 pM claims more than that fit supports.
Worked Examples
The anchor conversion. A million picomolar in one micromolar is worth internalizing.
One nanomolar, written the long way. Useful when comparing a working plate concentration against a binding-affinity reference in pM.
A single picomolar. Well below what most bench assays can directly measure without careful method work.
A ten-micromolar screening concentration, expressed at the scale of a detection-limit reference.
Common mistakes
Counting zeros instead of entering an exponent
The factor is 1,000,000, and the commonest way to lose it is a keystroke. Typed as 100000 or as 10^5 it puts the answer out by ten, and the result still reads as a perfectly plausible potency. Enter it as 1e6 or as × 10⁶ rather than as a run of zeros, and check against the anchor that one micromolar is a million picomolar.
Picomolar and picomoles are different quantities
pM is a concentration and pmol is an amount, and at this scale the two appear side by side in the same paragraph. A 100 µL well at 1 pM contains 0.1 fmol of material. Converting µM to pM says nothing about how much you dispensed; that needs a multiplication by volume. The symbols look almost alike; the quantities are not the same kind of thing.
Stopping one rung short at nanomolar
This step is two thousandfold moves stacked together, and taking only one lands the answer in nanomolar while it is still labeled picomolar. Nothing about the result looks wrong. 0.002 µM is 2000 pM, and the half-converted 2 reads perfectly well as a nanomolar potency. Say the ladder out loud — µM, nM, pM — and confirm both steps were taken.