Mole Calculator
Convert between moles, mass, and number of molecules. Enter any two values to find the third, or enter a chemical formula to calculate molar mass.
Enter formula to auto-calculate molar mass
Use scientific notation (e.g., 6.022e23)
How do I convert between moles and mass?
Use the formula: Mass (g) = Moles × Molar Mass (g/mol). For example, 2 moles of NaCl (molar mass = 58.44 g/mol) has a mass of 2 × 58.44 = 116.88 g. To convert from mass to moles: Moles = Mass (g) ÷ Molar Mass (g/mol).
What is molar mass and how do I find it?
Molar mass is the mass of one mole of a substance, measured in g/mol. For elements, it's the atomic mass from the periodic table. For compounds, add the atomic masses of all elements (multiply by subscript numbers). Example: NaCl = 22.99 + 35.45 = 58.44 g/mol.
Can I calculate moles from molecules?
Yes! Divide the number of molecules by Avogadro's number (6.022 × 10²³). For example, 3 × 10²⁴ molecules of CO₂ ÷ 6.022 × 10²³ = 4.98 moles. Alternatively, if you know the mass, use mass ÷ molar mass.
What is the mole concept in chemistry?
The mole is the SI unit for amount of substance. One mole contains exactly 6.022 × 10²³ particles (Avogadro's number). It allows chemists to count atoms, molecules, or ions by weighing them - bridging the microscopic and macroscopic worlds.
How do I use the mole in stoichiometry?
In stoichiometry, use the balanced equation coefficients as mole ratios. If you have 3 moles of reactant A and the ratio A:B = 2:1, you get 3 × (1/2) = 1.5 moles of product B. Convert moles to grams using molar mass for practical measurements.
What are the three ways to express amount of substance?
1) Moles (mol) - count of particles, 2) Mass (g) - using molar mass conversion, 3) Number of molecules - using Avogadro's number. All three are interconvertible using the mole as the central bridge concept.