Molar Mass Calculator

A compound's molar mass is just the sum of its atoms' atomic weights, but getting there by hand means parsing the formula correctly — tracking subscripts, multiplying through parentheses, remembering that Ca(OH)2 has two oxygens and two hydrogens, not one of each — and then looking up every element's weight on a periodic table. This does both steps: it reads the formula and does the arithmetic.

The formula parser handles real formulas, not just simple ones. Nested brackets multiply correctly — Mg3(PO4)2 gives three magnesiums, two phosphorus and eight oxygens, because the 2 outside the parentheses multiplies everything inside it. Hydrates work too: CuSO4·5H2O adds five water molecules' worth of hydrogen and oxygen on top of the anhydrous compound's own atoms.

Every element symbol is checked against the actual periodic table, so a capitalisation slip is caught immediately rather than silently misread — Co (cobalt) and CO (carbon monoxide, i.e. one carbon and one oxygen) are different formulas, and typing one when you meant the other is the single most common mistake in hand-entered chemical formulas.