Math

Percentage Calculator: Tips, Discounts, VAT & More

How to calculate percentages for discounts, tips, VAT/GST, and percentage changes — with a free instant calculator.

6 June 2026·4 min read·Open the tool →

Six percentage calculations you need

The ToolCrix Percentage Calculator covers these everyday use cases:

1. Percentage of a number

What is 15% of £240? → £36.

2. Percentage change

Price went from £50 to £65 → +30%.

3. Tip calculator

£85 bill + 20% tip ÷ 4 people → £25.50 each.

4. Discount / sale price

£120 item, 35% off → £78. Saving → £42.

5. VAT / GST

Add 20% VAT to £200 net → £240 gross. Reverse: VAT from £240 → £40 VAT, £200 net.

6. What percentage is X of Y?

45 out of 60 = 75%.

Quick mental math shortcuts

  • 10% — move decimal point one left.
  • 5% — halve the 10% figure.
  • 20% — double the 10% figure.
  • 15% — add 10% + 5%.