Discount Calculator

Calculate sale prices, savings, and discounts instantly. Stack multiple discounts, add VAT, and generate bulk discount tables.

Calculate Your Discount
£
%
Price already includes 20% UK VAT.
Bulk Discount Table Generator

See your price at common discount levels. Enter a price above and click "Generate Table".

How to Use This Calculator
Basic Discount Calculation
  1. Enter the original price of the item
  2. Select whether your discount is a percentage (e.g., 20% off) or fixed amount (e.g., £10 off)
  3. Enter the discount value
  4. Click Calculate Discount to see your savings
Stacking Multiple Discounts

Many sales offer additional discounts, such as "20% off + extra 10% for members". To calculate stacked discounts:

  1. Enable the "Stack another discount" option
  2. Enter the second discount value
  3. The calculator will apply the first discount, then apply the second discount to the reduced price
Note: Stacked discounts don't simply add up. 20% + 10% off results in 28% total savings, not 30%.
VAT Options Explained
  • Price Includes VAT: Most UK retail prices already include 20% VAT. This is the default setting.
  • Add VAT (20%): Use this for trade/wholesale prices where VAT needs to be added after the discount.
  • No VAT: For VAT-exempt items or when VAT doesn't apply.
Frequently Asked Questions

To calculate a percentage discount, multiply the original price by the discount percentage divided by 100. For example, 20% off £100 = £100 × (20/100) = £20 discount. The final price would be £100 - £20 = £80.

Discount stacking is when multiple discounts are applied sequentially. For example, if you have 20% off, then an additional 10% off, the second discount applies to the already-reduced price. So £100 with 20% off = £80, then 10% off £80 = £72 final price (28% total savings, not 30%).

To find the original price, divide the sale price by (1 - discount percentage/100). For example, if an item costs £80 after a 20% discount: £80 ÷ (1 - 0.20) = £80 ÷ 0.80 = £100 original price.

In the UK, most retail prices already include VAT at 20%. Discounts typically apply to the VAT-inclusive price. If you are a business dealing with trade prices, you may need to calculate discounts on the net (ex-VAT) price and then add VAT to the final amount.

The effective discount when stacking is calculated as: 1 - ((1 - first discount) × (1 - second discount)). For example, 20% + 10% stacked = 1 - (0.80 × 0.90) = 1 - 0.72 = 28% effective discount, not 30%.
Quick Formulas
Percentage Discount

Savings = Price × (Discount% / 100)

Final = Price - Savings

Fixed Amount Discount

Final = Price - Discount Amount

Stacked Discounts

Final = Price × (1 - D1%) × (1 - D2%)

Find Original Price

Original = Sale Price / (1 - Discount%)

Effective Discount

Effective% = ((Original - Final) / Original) × 100

Common Discounts
Discount £100 becomes
10% off£90.00
15% off£85.00
20% off£80.00
25% off£75.00
30% off£70.00
50% off£50.00
75% off£25.00
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