How to calculate a percentage
To calculate a percentage, open the ToolCrix Percentage Calculator and pick the mode that matches your question — X% of Y, what percent, % change, tip, discount or VAT. Enter your numbers and the answer updates instantly. Free, private and no sign-up.
Need to work out a percentage fast — a discount, a tip, a tax, or a percentage change? This free percentage calculator handles six common calculations in one place, instantly, in your browser. No app, no sign-up.
Why a dedicated percentage calculator helps
Percentages trip people up because the formula changes depending on the question: ‘what is 20% of 150’ is different from ‘15 is what percent of 60’ or ‘what's the % change from 80 to 100’. A single calculator with labelled modes removes the guesswork.
It's faster and less error-prone than doing the maths in your head when money is involved — bills, raises, sale prices and tax.
How to use it (step by step)
- Open the Percentage Calculator.
- Pick the mode that matches your question (percent of, what percent, % change, tip, discount, or VAT/tax).
- Enter your numbers — the answer updates instantly.
- Read the result and, for tips, the per-person split.
- Copy the result if you need it elsewhere.
What you can use it for
- Calculating a sale price after a discount.
- Splitting a restaurant bill and adding a tip.
- Adding or removing VAT/sales tax from a price.
- Working out a percentage pay rise or grade.
- Comparing a before/after percentage change.
The percentage formulas
- X% of Y = (X ÷ 100) × Y
- X is what % of Y = (X ÷ Y) × 100
- % change = ((new − old) ÷ old) × 100
- Discount price = price × (1 − discount%)
- Remove VAT = price ÷ (1 + rate)
Tips
- For a quick tip, 10% is the bill with the decimal moved one place left; double it for 20%.
- ‘Percentage points’ and ‘percent change’ are different — don't confuse them.
- To remove tax, divide by (1 + rate), don't subtract the rate.
- Round only at the end to avoid compounding errors.
Frequently Asked Questions
How do I calculate a percentage of a number?
Use the ‘% of’ mode: enter the percentage and the number, e.g. 20% of 150 = 30.
How do I work out percentage change?
Use the ‘% change’ mode: from 80 to 100 is a +25% change.
How do I remove VAT from a price?
Use the VAT mode set to ‘remove’: it divides by (1 + rate), so £120 at 20% becomes £100.
Is the calculator free?
Yes — free, instant and private, with no sign-up.
Does it split tips between people?
Yes. Enter the bill, tip percentage and number of people to get the per-person amount.
How do I calculate percentage change between two numbers?
Subtract the old value from the new value, divide by the old value, and multiply by 100. The ToolCrix Percentage Calculator does it for you — from 80 to 100 is a +25% change.
How do I remove VAT from a price?
Divide the price by (1 + the VAT rate as a decimal). For 20% VAT, divide by 1.20. The ToolCrix calculator's VAT mode does this automatically.
Try it now: open the free Percentage Calculator or the Mortgage Calculator, or browse more guides.