Percent off calculator
The reverse of a discount calculation: you know what it was and what it is, and you want the percentage that was taken off.
Result
- Percent off
- 25.00%
- Amount saved
- $20.00
- You pay this share of the original
- 75.00%
Worked examples
Finding the discount that was applied
A shirt was $80 and is now $60.
- 80 − 60 = 20
- 20 ÷ 80 = 0.25
25% off.
Working backwards from the sale price
This is the inverse of a discount calculation. You know the original and the sale price, and you want the percentage that was taken off — useful for checking whether an advertised discount is what it claims to be.
Divide the saving by the original price, not the sale price. Dividing by the sale price gives the markup needed to get back to the original, which is a different and larger number.
Formula
percent off = ((original − sale) ÷ original) × 100
Reading a sale price back to a discount
| Original | Sale price | Percent off | You pay |
|---|---|---|---|
| $80 | $60 | 25% | 75% |
| $100 | $75 | 25% | 75% |
| $100 | $67 | 33% | 67% |
| $120 | $90 | 25% | 75% |
| $50 | $35 | 30% | 70% |
| $200 | $120 | 40% | 60% |
Frequently asked questions
How do I find what percent off a sale price represents?
Subtract the sale price from the original, divide by the original, and multiply by 100. From $80 to $60: 20 ÷ 80 × 100 = 25% off.
Why does dividing by the sale price give a different answer?
Because it answers a different question — the percentage increase needed to get from the sale price back to the original. From $60 to $80 is a 33.3% increase, but only a 25% discount.
How do I find the original price from the sale price and discount?
Divide the sale price by (1 − discount ÷ 100). A $60 item at 25% off was 60 ÷ 0.75 = $80.
How do I check whether an advertised discount is real?
Divide the saving by the original price. If a $200 item is advertised at 40% off but is selling for $140, the actual discount is 30%.
What percentage increase reverses a 25% discount?
33.3%. Going from $60 back to $80 requires adding a third, because the base is now smaller.
Why is percent off different from percent of?
Percent off is the share removed; percent of is the share remaining. A 25% discount leaves you paying 75% of the original.