Method
Choose the relationship first. Percentage of a number uses P ÷ 100 × value. What-percent uses part ÷ whole × 100. Percentage change uses (new − original) ÷ |original| × 100.
Example
20% of 150 is 30 because 0.20 × 150 = 30.
Limits
Check inputs and units. Important academic, financial or professional decisions should be confirmed against an appropriate source.
Common questions
What does the percentage calculator calculate?
Solve percentage-of, what-percent and percentage-change questions.
Does this percentage calculator show its method?
Yes. The result includes the central formula or working needed to check the answer.
Are my values uploaded?
No. The calculation runs in this browser and does not require an account.