Actual Yield = Theoretical Yield × (% Yield / 100)
In chemistry, three types of yield matter: theoretical yield (maximum product possible from stoichiometry), actual yield (what you actually obtain in the lab), and percent yield (actual/theoretical × 100). Percent yield is always ≤ 100% in practice due to incomplete reactions, side reactions, transfer losses, and purification steps. Typical organic synthesis yields: simple reactions 80-95%, multi-step synthesis 50-80% per step, total synthesis of complex molecules <1% overall. A reaction with 90% yield per step gives only 35% yield after 10 steps (0.9^10). Industrial processes optimize for high yield to minimize waste and cost — pharmaceutical manufacturing typically requires >99% purity with 70-90% yield.