Working out a discount
The final price is the original times (1 − discount as a decimal):
- 30% off $80 → 80 × (1 − 0.30) = 80 × 0.70 = $56.
- The Discount Calculator shows the sale price and how much you saved.
Working out a tip
Multiply the bill by the tip percentage and add it:
- 18% tip on $45 → 45 × 0.18 = $8.10, total $53.10.
- The Tip Calculator also splits the bill between any number of people.
Both are just percentages
Discounts and tips are the same percentage maths in different directions — one subtracts, one adds. For any other percentage question, the Percentage Calculator covers it.
Quick mental tricks
- 10% is just the number with the decimal moved one place (10% of $45 = $4.50).
- 20% is double that; 15% is 10% plus half of 10%.
Private
Calculations run in your browser — nothing is uploaded.