Interactive infographic

Black Friday Math: Why 30% + 20% Off Isn't 50%

Stack a sale price and a coupon to see why two discounts never simply add up. 30% off plus an extra 20% off is 44% off, not 50%.

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What this infographic shows

Stacked discounts multiply instead of adding. A store that offers “30% off, plus an extra 20% with this coupon” takes 30% off first. The coupon then takes 20% off what is left, which is a smaller number. Together they take 44% off, not 50%.

The two bars show the price at each step:

  • Indigo: what you pay.
  • Amber: the sale discount.
  • Light amber: the coupon.

How to use it

  1. Set the original price.
  2. Set the sale discount and the extra coupon.
  3. Compare what it sounds like with the real discount. The gap grows as the discounts get bigger.

A quick way to do it in your head

Turn each discount into what you keep, then multiply. 30% off means you keep 70%. 20% off means you keep 80%. 0.7 × 0.8 = 0.56, so you pay 56% of the original price.

Holiday shopping is forecast to pass $1 trillion in the U.S. this year. If you put purchases on a card, see why minimum credit card payments cost so much.

Frequently asked questions

How do you calculate two discounts together?

Multiply what is left after each one. For 30% off and then 20% off, you pay 70% of 80%, which is 56% of the original price. That is a 44% discount.

Is "extra 20% off sale price" the same as 20% more off?

No. It is 20% of the already-reduced price. On a $200 item that is 30% off, the extra 20% takes off $28, not $40.

Does the order of the discounts matter?

No. 30% then 20% and 20% then 30% both leave you paying 56% of the original price. Order only matters when one discount is a fixed dollar amount.

When is Black Friday 2026?

Friday, November 27, 2026. Thanksgiving is on Thursday, November 26, and Cyber Monday is on November 30.

Sources

  1. NRF forecasts 2026 holiday sales growth as consumers remain resilient — National Retail Federation
Text version of this infographic

Why 30% + 20% off isn't 50% off

A coupon or "extra % off" applies to the price after the first discount, not to the original price. Try it.

Original price

Sale discount

Extra coupon off the sale price

What it sounds like

Real discount

You pay

What you pay

Sale discount

Coupon

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