All calculatorsDiscount Calculator
Calculate final price, you save, and effective discount fast. Supports % off, \( off, final price → discount %, stacked discounts, optional sales tax, plus step-by-step, mini visuals, and export.
Background
“Discount” sounds simple until you stack promos, compare coupons, or add tax. This calculator shows the real outcome with a clean breakdown — so you can pick the best deal quickly.
How to use this calculator
- Pick a mode (% off, \( off, final → %, or stacked discounts).
- Enter the original price and discount info.
- Optional: add sales tax and choose “tax before/after”.
- Click Calculate to see final price, savings, and effective discount.
Tip: If you’re comparing deals, use the “effective discount %” and final total (with tax) to decide.
How this calculator works
- Computes discounted price using Final = Original × (1 − %/100) or Final = Original − Amount.
- For stacked deals, it applies each discount in order (multiplicative for %).
- If tax is provided, it can apply tax before or after discount.
- Reports savings and effective discount for easy comparison.
Formula & Equation Used
% off: Final = Original × (1 − p/100)
\) off: Final = Original − a
Savings: Save = Original − Final
Effective %: Effective = (Save / Original) × 100
Tax: Total = Subtotal × (1 + t/100)
Example Problem & Step-by-Step Solution
Example 1 — 25% off \$80
- Original = \$80
- Discount = 25%
- Final = 80 × (1 − 0.25) = 60
- You save = 80 − 60 = 20
Example 2 — Stack 20% then 10% on \$100
- After 20%: 100 × 0.80 = 80
- After 10%: 80 × 0.90 = 72
- Total savings: 100 − 72 = 28
- Effective discount: 28%
Example 3 — Original \$120, final \$90 → find %
- Savings: 120 − 90 = 30
- Discount %: (30/120)×100 = 25%
Frequently Asked Questions
Q: Is 20% then 10% the same as 30%?
No. It’s multiplicative: 0.8 × 0.9 = 0.72, so it’s 28% off overall.
Q: Can savings be negative?
It shouldn’t be. If a discount is larger than the price, we cap the final price at 0.
Q: Should I apply tax before or after discount?
Most retail applies tax after discounts, but some situations differ—choose what matches your receipt.
Q: What’s “effective discount %”?
It’s the total savings divided by the original price, expressed as a percent (great for comparing deals).