Formula Mass and Mole Calculator
A free teacher tool for calculating relative formula mass and showing conversions between mass, moles, gas volume at r.t.p. and solution concentration.
What the calculator does
- Interprets chemical formulae, including brackets and waters of crystallisation.
- Displays the contribution made by each element.
- Converts between mass and amount in moles.
- Calculates gas volumes at r.t.p.
- Works with concentration and solution volume using n = cv.
The central relationship
mass = Mr · moles
The calculator uses the familiar UK school convention moles = mass ÷ Mr and makes every stage of the calculation visible.
Open the calculator
Enter a chemical formula or select an example to begin.
Launch Formula Mass CalculatorThe calculator opens in a new browser tab.
For structured A-level chemistry teaching and guided mastery, visit
ACE Chemistry Academy
.