Percentage Calculator
Pick a mode, type your numbers, get the answer with the full working shown.
All five modes work in the same currency or unit — the tool never converts or rounds your inputs.
How to use the Percentage Calculator
- Pick the calculation you need from the five tabs: X% of a number, what percent, percentage change, value after a change, or reverse percentage.
- Enter your numbers — the result updates live as you type, or click Calculate Percentage.
- Read the big result plus the worked equation underneath, and use Copy result to paste it anywhere.
Percentage Calculator FAQs
How do I calculate X percent of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 200 is (200 × 15) ÷ 100 = 30. Use the "X% of a number" tab and the calculator does it instantly.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. For example, 30 is (30 ÷ 200) × 100 = 15% of 200. The "X is what % of Y" tab runs this for you.
How do I calculate a percentage increase or decrease?
Subtract the old value from the new value, divide by the old value, and multiply by 100. A salary rising from 50,000 to 58,000 is (8,000 ÷ 50,000) × 100 = 16%. The "Percentage change" tab handles both increases and decreases.
What is a reverse percentage calculation?
It finds the original value when you only know the final value after a percentage change. Divide the final value by (1 + percent/100) for an increase, or (1 − percent/100) for a decrease. For example, a price of 1,180 after an 18% rise came from 1,180 ÷ 1.18 = 1,000.
How many decimal places do the results show?
Results are shown rounded to 2 decimal places for readability (thousands separators included), but the calculation itself uses full precision, so chained calculations stay accurate.
Percentage Calculator — Every Percentage Question, One Free Tool
This percentage calculator answers the five questions people actually search for: what is X% of a number, what percent one number is of another, how much a value changed in percent, what a value becomes after a percentage change, and what the original value was before the change. Everything runs in your browser — no sign-up, no uploads, no waiting.
How to use it, step by step
- Choose one of the five tabs matching your question — for example "X% of a number" for discounts or "Percentage change" for growth.
- Type your numbers; the answer updates live as you type, or press Calculate Percentage.
- Read the large result together with the worked equation, which shows exactly how it was computed so you can double-check it.
Popular uses
- Work out discounts, tax and tips: 15% of 200, 20% off a price tag, a 10% service charge.
- Check exam marks and scores: 42 out of 50 is 84%.
- Measure growth: salary raises, business revenue change, weight loss in percent.
- Reverse-engineer prices: find the pre-tax or pre-discount price from the final amount.