This calculator converts between moles and mass using a substance's molar mass, and tells you how many particles that amount contains. The mole is the chemist's way of counting, a fixed number of particles, Avogadro's number, that lets us connect the invisible world of atoms and molecules to quantities we can actually weigh on a balance. Converting between moles and mass is the single most common calculation in chemistry, needed for preparing solutions, balancing reaction quantities, and almost every quantitative problem. The link between the two is the molar mass, the mass of one mole of the substance, which equals its relative atomic or molecular mass in grams. This calculator does the conversion. You enter the number of moles and the molar mass of the substance in grams per mole, and the calculator returns the mass in grams, the number of particles, atoms or molecules, that this represents, and your inputs for reference. The results update as you type. Use it for chemistry study, for laboratory work, or whenever you need to move between an amount in moles and a mass you can measure. The mass is the number of moles multiplied by the molar mass, and the number of particles is the moles multiplied by Avogadro's number, about 6.022 times ten to the twenty-three. To go the other way, from a mass to moles, you would divide the mass by the molar mass, the reverse of the headline calculation. Knowing the molar mass is the key: it comes from adding up the atomic masses of the atoms in the formula, which a periodic table provides. With the molar mass in hand, this conversion turns a count of particles into a weighable mass and back, the everyday bridge that makes quantitative chemistry possible.
Calculate.co.nz is proud to be partnered with Premium Homes, a recognised leader in eco-friendly, sustainable, and energy-efficient homebuilding. With a dedicated team and award-winning experience, they create homes that prioritise health, comfort, and long-term performance. Their founders, Andrew and Kelly, set out to raise the standard of residential construction in New Zealand by combining practical building expertise with a clear commitment to doing things better for homeowners.
36.03 g
mass
Particles1.204e+24
Moles2
Molar mass18.015 g/mol
Mass = moles x molar mass. Particles = moles x Avogadro's number (6.022 x 10^23). To find moles from a mass, divide the mass by the molar mass.
How it works
The mass is the number of moles multiplied by the molar mass in grams per mole. The number of particles is the number of moles multiplied by Avogadro's number, about 6.022 times ten to the twenty-three. The molar mass comes from adding the atomic masses of the atoms in the substance's formula.
Worked example
Two moles of water, with a molar mass of 18.015 grams per mole, have a mass of 2 times 18.015, which is 36.03 grams. That same two moles contains 2 times Avogadro's number, about 1.204 times ten to the twenty-four, water molecules.
