Calculators
Percentage Calculator
Percent of a number, percent change, tips, and discounts in one place.
Result
30
15% of 200 = 30
Example: What is 15% of 200?
How it works
- 1Pick the calculation mode you need.
- 2Enter the two values.
- 3See the result plus a one-line explanation.
Use cases
- Compute discounts at checkout or in spreadsheets
- Split a tip or service charge fairly
- Find percent change between two metrics (sales, weight, scores)
Frequently asked questions
What is the formula for percent change?
((new − original) ÷ |original|) × 100. Positive means an increase, negative means a decrease.
How does the tip / discount mode work?
It multiplies the rate by the total, then shows you both the added (total + tip) and subtracted (total − discount) amounts.
Why might the result show "—"?
Division by zero is undefined — for example, asking "30 is what % of 0?" has no answer.
Read the guide
How to calculate percentages without re-learning them every time
Three formulas cover 99% of percentage questions. Here is how each one works and which to use when.