Fast Molar Mass Calculator for Any Chemical Formula

You're writing a lab report and you need the molar mass of calcium hydroxide. You could flip through appended tables, look up each element, multiply by counts, add it all up — or you could just type Ca(OH)2 and get the answer.

How it works

The molar mass calculator parses any chemical formula you throw at it. Standard notation, parentheses, nested groups, multi-digit subscripts — it handles all of it. Type H2O and you get 18.015 g/mol. Type Fe2(SO4)3 and you get 399.878 g/mol. No guesswork, no rounding errors from manual addition.

Below the total, you see a breakdown table: each element, how many atoms appear in the formula, the atomic mass of one atom, the total mass contribution, and the mass percentage. That last column is what you need for gravimetric analysis or when figuring out how much of a compound is actually the element you care about.

Say you're working with glucose, C₆H₁₂O₆. You type C6H12O6 and immediately see that carbon makes up about 40% of the mass, hydrogen about 6.7%, and oxygen about 53.3%. Those numbers come straight from accurate atomic weights — you don't have to trust your mental arithmetic.

Where this saves time

Lab prep is the obvious one. You're calculating how much reagent to weigh out and you need to convert between moles and grams. Having the molar mass right there means one fewer tab open.

It's also useful when you're checking homework or verifying a textbook answer. If you're a student learning stoichiometry, being able to confirm your manual calculations builds confidence and catches mistakes early.

The molar mass calculator pairs well with the periodic table if you want to look up individual element properties, or the equation balancer if you're working through a full reaction. Everything runs in your browser — no account, no data shared, just quick chemistry math.