Discount Calculator
Calculate sale prices, savings and reverse percentage discounts instantly.
Last updated: April 2026 · Source: Citizens Advice — Shop sales and bargains
Calculate Sale Price
What % Discount Is This?
Disclaimer
This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.
How It Works
This calculator works out the final price after a percentage discount, the amount you save and — for stacked discounts — the combined effective percentage off. Enter the original price and one or more discount percentages to see results instantly.
Stacked discounts are applied sequentially, not added together. A 20% discount followed by a 10% discount is not 30% off — it is 28% off because the second discount applies to the already-reduced price. The calculator handles this correctly and shows the true combined saving.
You can also reverse-calculate: enter the sale price and original price to find the percentage discount that was applied. This is useful for checking whether a sale is genuine or whether the original price was inflated.
Example: £80 item with 25% off
- Original price: £80.00
- Discount: 25% = £20.00
- Sale price: £60.00
- With additional 10% off: £60 × 0.90 = £54.00 (total saving: 32.5%)
Frequently Asked Questions
- What does the Discount Calculator do?
- Calculate sale prices, savings and reverse percentage discounts instantly. All calculations are performed in your browser using official UK rates and thresholds.
- Is this calculator free to use?
- Yes. All calculators on Calks.uk are completely free to use. No account or registration is required. All calculations run in your browser — no data is collected.
- Can I use this on my phone?
- Yes. All our calculators are fully responsive and work on smartphones, tablets and desktop computers. The interface adapts to your screen size automatically.