Discount & Sales Tax Calculator

How to Use the Discount & Sales Tax Calculator

1

Enter the ticketed item price.

2

Specify the primary percentage off, and any secondary coupon voucher percentage.

3

Enter your local sales tax rate to compute the final out-of-pocket register total.

Formula & Underlying Logic

Sequential Stacked Discount Mathematics

When stores offer "20% off plus an extra 10% coupon", discounts are applied sequentially, not additively:

P₁ = Price × (1 - D₁) | P_final = [ P₁ × (1 - D₂) ] × (1 + Tax)

Applying 20% + 10% sequentially equals an effective 28% total discount, not 30%.

Worked Step-by-Step Example

Example Scenario: $150 Jacket with 25% Sale, 10% Coupon, and 8.25% Tax

After 25% discount: $112.50

After extra 10% coupon: $101.25 (Total saved: $48.75)

Tax (8.25%): $8.35 → Final checkout price: $109.60

Frequently Asked Questions

Is sales tax calculated before or after the discount? +

In almost all tax jurisdictions, retail sales tax is computed on the discounted net transaction price, not the original retail price.

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