Discount Calculator

Calculate discount amounts and final prices easily. You can calculate percentage or amount-based discounts, apply multiple discounts, and perform VAT calculations.

How to Calculate Discount?

1. Enter the original price
2. Enter the discount percentage
3. Click "Calculate Discount"
4. The results will show:
- Discount amount
- Final price
- Total savings

Note: Discount percentage must be between 0-100.

Financial Calculations

Discount Calculator Discount Rate Calculator Savings Calculator

Working out what a discount really saves you

A single percentage off is simple arithmetic. The complications arrive when discounts stack, when tax is involved, and when the "original" price was never actually charged. This page covers the arithmetic and the traps that make advertised savings look larger than they are.

Formula

saving = original x (rate / 100) | final price = original - saving = original x (1 - rate/100)

Multiplying by (1 - rate/100) in one step avoids the rounding drift that creeps in when you calculate the saving separately and subtract.

Stacked discounts do not add up

Two successive discounts of 20% and 10% are not 30% off. Each applies to whatever is left after the previous one, so the combined effect is multiplicative.

On a price of 100: after 20% you have 80, and 10% off 80 is 72. The real discount is 28%, not 30%. The general rule is that stacking rates a and b gives a combined rate of a + b - (a x b / 100).

Order does not change the outcome for percentage discounts, because multiplication commutes. It does change the outcome when a fixed-amount voucher is mixed in - applying a 10 euro voucher before a 20% discount saves you less than applying it after.

Discount off tax-inclusive versus tax-exclusive prices

In the EU and UK, displayed consumer prices include VAT, so a percentage off applies to the gross figure and the tax falls proportionally. In most of the US, sales tax is added at the till, so a discount applies to the pre-tax price and the tax is calculated on the reduced amount.

Both routes produce the same final total when the rate is applied consistently, but they produce different intermediate figures, and invoices that mix the two will not reconcile.

When the "original price" is not real

The saving is only meaningful if the reference price was genuinely charged. Regulators have taken a growing interest in this.

EU Directive 2019/2161, in force since May 2022, requires that any announced price reduction shows the lowest price applied in the previous 30 days.
UK Chartered Trading Standards Institute guidance expects a reference price to have been the selling price for a reasonable period, not a token listing.
The US FTC treats a "former price" as deceptive unless the item was offered openly and in good faith at that price for a reasonably substantial period.

Worked example

A jacket lists at 249.99 with 35% off, plus an extra 15% loyalty discount at checkout, in a jurisdiction where the displayed price includes 20% VAT.

First discount: 249.99 x 0.65 = 162.49. Second: 162.49 x 0.85 = 138.12. Total saving is 111.87, an effective 44.75% - not the 50% the two labels suggest.

Of the 138.12 paid, the VAT component is 138.12 - (138.12 / 1.20) = 23.02. The net price of the goods is 115.10.

What common discount rates leave you paying

Discount	Multiplier	You pay on 100	Saving
10%	0.90	90.00	10.00
15%	0.85	85.00	15.00
20%	0.80	80.00	20.00
25%	0.75	75.00	25.00
33.3%	0.667	66.70	33.30
50%	0.50	50.00	50.00
70%	0.30	30.00	70.00

Buy one get one free is a 50% discount on two units, not 100% on one - the multiplier is 0.50 across the pair.

Frequently Asked Questions

The second discount applies to the already-reduced price, not the original. Combined, they give 28% off. The formula for stacking two rates is a + b - (a x b / 100).

For a fixed-amount voucher, applying it last saves you more, because the percentage then works on the larger figure. Most retailers specify the order in their terms, and it is usually the one that favours them.

Yes. Tax is charged on the amount actually paid, not the list price. On a VAT-inclusive price the tax component falls proportionally with the discount.

Margin is profit as a share of the selling price, markup is profit as a share of cost. A 50% markup is only a 33.3% margin, so discounting eats into margin far faster than the markup figure suggests.

Only about the single deepest reduction in the range. Advertising codes in the UK and EU generally expect a meaningful proportion of the range to be available at or near the headline rate, but the wording remains legally weak.

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References

Last reviewed: 2026-08-07. This page is informational. For legal, medical, tax, or financial decisions, confirm the result with a qualified professional.