The Mole Map

Stoichiometry is navigation on the mole map: convert the given mass to moles (m ÷ M), move between substances using the balanced equation's mole ratio, and convert back to mass (moles × M). This calculator walks the full path from grams of A to grams of B in one step.

Why Moles?

Grams can't be compared directly across substances — a gram of hydrogen contains 16× more particles than a gram of oxygen. The mole (6.022 × 10²³ particles) gives every substance a common counting unit, making ratio conversions exact regardless of which elements are involved.

From Theory to the Lab

The theoretical mass assumes perfect conditions, but real reactions lose product to side reactions, incomplete conversion, and transfer losses. Comparing your measured yield to the theoretical value gives the percent yield — the standard measure of a reaction's efficiency in industry, where even a few percent matter at scale.