How do I calculate 30% off?

Multiply the original price by 0.70. For example, 30% off $89.99 = $89.99 × 0.70 = $62.99. The calculator does this instantly — enter the price and discount percentage.

Do discounts stack by adding percentages?

No. A 30% discount followed by a 15% discount is NOT 45% off. The second discount applies to the already-reduced price. 30% + 15% stacked = 40.5% effective discount. Use the Double Discount tab to see the real number.

Why is the effective discount less than the sum of both discounts?

Because the second discount applies to the already-reduced price, not the original. A 30% discount brings $100 to $70. A 15% discount on $70 saves $10.50 — not $15. The total saved is $40.50 (40.5%), not $45.

Discount Calculator

Q: What is a double discount?

Two sequential discounts applied one after another — for example, a 30% sale plus an extra 15% coupon. The second discount applies to the sale price, not the original price. This is common in retail during clearance events.

See the final price after one or two stacked discounts.

Price & discount

Original price

Discount

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How to Use This Calculator

Single Discount tab

Enter the original price and discount percentage. The calculator instantly shows the final price and how much you save. Use this for straightforward sales — "30% off," "25% discount," etc.

Double Discount tab

For stacked discounts — like "extra 20% off sale items." Enter the original price, the first discount, and the second discount. The calculator applies them sequentially and shows the final price, total savings, and the effective combined discount (which is always less than the sum of the two).

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The Formula

Single discount:

Final Price = Original Price × (1 − Discount ÷ 100)

Double (stacked) discount:

Final Price = Original Price × (1 − D1 ÷ 100) × (1 − D2 ÷ 100)

Effective combined discount:

Effective Discount = 1 − (1 − D1 ÷ 100) × (1 − D2 ÷ 100)

Where:

D1 = first discount percentage
D2 = second discount percentage

The key insight: stacked discounts multiply, they don't add. 30% + 15% is not 45% off — it's 40.5% off, because the second discount applies to the already-reduced price.

Example

Jacket on sale with an extra coupon

You find an $89.99 jacket marked 30% off. At checkout, you have an extra 15% coupon that stacks on top.

Original price$89.99

First discount (30%)−$27.00

Price after 30% off$63.00

Second discount (15%)−$9.45

Final price$53.55

Total saved$36.44

Effective discount40.5% (not 45%)

The second discount applies to $63.00, not the original $89.99 — that's why the effective discount is 40.5%, not 45%.

FAQ

How to calculate 30% off? ▼

Multiply the price by 0.70. For example, 30% off $80 = $80 × 0.70 = $56. The quick trick: subtract the discount percentage from 100, move the decimal two places left, and multiply. 30% off → multiply by 0.70.

Do discounts stack by adding? ▼

No — discounts multiply, they don't add. A 30% discount followed by a 15% discount is not 45% off. The second discount applies to the already-reduced price. The effective combined discount is 40.5%. This is true for all stacked discounts, coupons, and sequential markdowns.

What is a double discount? ▼

A double discount is when two separate discounts are applied sequentially to the same item. Common examples: a sale price plus an additional coupon, an employee discount on top of a clearance price, or "extra 20% off all sale items." The order doesn't matter — 30% then 15% gives the same result as 15% then 30%.

Why is the effective discount less than the sum? ▼

Because the second discount applies to the already-reduced price, not the original. When you take 30% off first, the price drops to 70% of the original. Then 15% off that reduced amount removes 15% of 70%, which is only 10.5% of the original. So the total is 30% + 10.5% = 40.5%, not 30% + 15% = 45%.

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