Unit converter

Amount of substance.

Convert mmol to mol, or pick any of the 4 units in the menus. Type in either box and the other follows. Moles are a count of entities, fixed at exactly 6.022 140 76×10²³ since the 2019 redefinition. Grams are deliberately not in these menus: converting moles to grams needs the molar mass of the particular substance, so it is a calculation rather than a conversion.

mmol → molExact definition
Millimoles to moles — common values, to 6 significant figures.
mmolmol
1 mmol0.001 mol
2 mmol0.002 mol
3 mmol0.003 mol
4 mmol0.004 mol
5 mmol0.005 mol
10 mmol0.01 mol
15 mmol0.015 mol
20 mmol0.02 mol
25 mmol0.025 mol
50 mmol0.05 mol
75 mmol0.075 mol
100 mmol0.1 mol
250 mmol0.25 mol
500 mmol0.5 mol
1000 mmol1 mol
1 mmol=0.001 mol 1 mol=1000 mmol

Definitions

  • The millimole is a thousandth of a mole, the scale most clinical and bench chemistry works at.
  • The mole is the SI base unit of amount of substance: exactly 6.022 140 76×10²³ entities.
  • Every unit here is defined against the mol.
  • Every unit in the menus is exact by definition, so the only rounding on this page is the one you choose for the display.

How it works

Every value is converted into moles and then back out into the unit you asked for. One route covers every pairing in the menus, so an unusual combination is no less accurate than a common one, and adding a unit affects only that unit.

Both boxes are live. Whichever one you last typed in is the source, changing either menu recalculates straight away, and Swap exchanges the units and the values so the number you are reading stays where you are looking.

Display precision sets a maximum number of significant figures and trims trailing zeroes, so it changes what you see and never what was calculated. The editable box always holds a plain number at full working precision, so you can carry on from either side.

Common questions this answers: how many moles in a millimole (0.001), how many millimoles in a mole (1000), and what 1000 mmol is in moles (1 mol).