Method and assumptions
Solve common percentage questions: a part of a whole, percentage change between two values, and a price after a discount. Because percentages are relative, always confirm which value is the baseline.
Percentage Calculator
Calculate percentages, change rates, and discounted prices.
Reviewed: 2026-07-21
How to use it
- Choose the type of percentage calculation.
- Enter the base value and percentage or comparison value.
- Check the answer and the displayed formula.
When it helps
- Checking a sale price
- Measuring growth or decline
- Finding a share of a total
How to verify the result
Check input units and reference dates first. For an important decision, compare the result with an official source or original document. A rounded display can differ slightly from the underlying value.
Frequently asked questions
How do I calculate percentage increase?
Subtract the old value from the new value, divide by the old value, and multiply by 100.
Does a 50% rise followed by a 50% fall return to the start?
No. A value of 100 rises to 150, then a 50% fall results in 75 because the second percentage uses a different base.
What is the difference between discount rate and discount amount?
The rate is the share removed from the original price. The amount is the actual money deducted.