Percentage of a Percentage
Defaults: 30% of 20% = 6%. Use this for nested rates — an agent commission of a sales commission, a discount on a sale price, or compound tax effects.
Compound percentages multiply. 30% of 20% is not 50%, it's 6% (0.3 × 0.2). The calculator above handles this directly. Below: UK use cases.
Worked examples
10% commission on a 30% margin = 3% of revenue — how much of total revenue goes to the agent.
20% off a 50% sale price = 60% of original — the sale rules «extra 20% off the sale price» trick.
40% income tax on a 20% bonus = 8% of base salary lost to tax — on a £35k salary with a £7k bonus.
Frequently asked questions
Are 30% of 20% and 20% of 30% the same?
Yes — multiplication is commutative.
Why isn't 50% off twice the same as 100% off?
Because the second 50% is taken off a smaller number. 50% off £100 is £50; 50% off £50 is £25. Total saved: £75, not £100.