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Sale Price Calculator

Sale price after one or two discounts and tax. Two stacked discounts do not add: thirty percent then twenty percent is forty-four percent off, not fifty.

Also called: discount calculator, how much will i pay.

₹
%
%
%
You pay
₹1,750

₹1,750 after a 30% discount saves ₹750. A single discount, so nothing is compounding.

After the first discount
₹1,750
After the second
₹1,750
Total saved
₹750
Effective discount
30%
Tax
₹0
On stacked discounts
A single discount, so nothing is compounding.
How this is calculated
Method and background

How this is calculated

Each discount applies to what is left after the previous one, so they multiply rather than add. Thirty percent off leaves seventy percent, and twenty percent off that leaves fifty-six percent, an effective discount of forty-four. Tax then applies to the discounted price, which is why an advertised discount is worth slightly less than it looks once tax is added back.

discounts multiply rather than add, then tax applies to what is left
V
Original price (currency)
d
Each discount (decimal)
t
Tax rate (decimal)

Worked examples

Each of these is asserted on every build. If a change to the engine ever moved one of these answers, the build would fail before the page could print it.

thirty percent off

Original price
₹2,500
Discount
30%
Further discount on the sale price
0%
Tax added at checkout
0%

You pay₹1,750

arithmetic identity

Open this example

thirty then twenty is forty-four

Original price
₹2,500
Discount
30%
Further discount on the sale price
20%
Tax added at checkout
0%

You pay₹1,400

boundary: the stacking fact this page exists for

Open this example

no discount leaves the price

Original price
₹2,500
Discount
0%
Further discount on the sale price
0%
Tax added at checkout
0%

You pay₹2,500

degenerate case

Open this example

Method and limits

What it assumes

  • The second discount applies to the already-discounted price, which is the usual retail rule.

What it deliberately does not model

  • Some promotions apply both discounts to the original price, which would add rather than multiply.

Formula version 1.0.0 · definition 1.0.0 · India · Report a problem with this calculator

Frequently asked questions

Is 30% then 20% the same as 50% off?
No, it is 44% off. The second discount applies to the reduced price, so stacked discounts always come to less than their sum.