The mole is the chemist's way of counting particles. One mole contains Avogadro's number, 6.022 × 10²³, of atoms, molecules or ions. This mole calculator converts between mass in grams and amount in moles using the molar mass.
It also gives the number of particles and, if the substance is a gas, its volume at standard temperature and pressure (STP). NCERT now uses STP as 0 °C and 1 bar (22.7 L/mol); older books use 1 atm (22.4 L/mol), so both are shown.
| Find | Moles (from mass) |
| Mass (m) | 36 g |
| Molar mass (M) | 18.02 g/mol |
| Amount (mol) | 1.99833 |
| Mass (g) | 36 |
| Number of particles | 1.20343e24 |
| Volume if a gas, at STP 0 °C & 1 bar (L) | 45.3842 |
| Volume if a gas, at 0 °C & 1 atm (L) | 44.7907 |
36 g of water is 1.99833 mol, containing 1.20343e24 molecules.
Try this example →| Find | Mass (from moles) |
| Molar mass (M) | 58.44 g/mol |
| Amount (n) | 0.5 mol |
| Amount (mol) | 0.5 |
| Mass (g) | 29.22 |
| Number of particles | 3.01107e23 |
| Volume if a gas, at STP 0 °C & 1 bar (L) | 11.3555 |
| Volume if a gas, at 0 °C & 1 atm (L) | 11.207 |
0.5 mol of sodium chloride has a mass of 29.22 g.
Try this example →Divide the mass in grams by the molar mass: n = m/M. 36 g of water ÷ 18 g/mol = 2 mol.
6.02214076 × 10²³, the number of particles in one mole.
22.7 L at 0 °C and 1 bar (current IUPAC/NCERT), or 22.4 L at 0 °C and 1 atm (older definition).
1 ÷ 18.015 × 6.022 × 10²³ ≈ 3.34 × 10²² molecules.