Discount Calculator

Last Updated:

Calculate sale prices, savings amounts, and discount percentages instantly. Works for any percentage off.

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Sale Price

$90.00

You Save$30.00
Original Price$120.00

📐 Formula

Sale Price = Original × (1 − Discount%). Savings = Original × Discount%. Discount% = (Savings / Original) × 100

How to Use the Discount Calculator

1

Enter the original price

Input the pre-sale price shown on the tag or listing. This is the price before any discount is applied.

2

Enter the discount percentage

Input the markdown percentage — 20% off, 30% off, etc. The calculator instantly shows the discounted price and the exact dollar amount saved.

3

Use reverse discount if needed

If you know the sale price and want to find the original price or the discount percentage, use the reverse calculation fields. Useful when comparing 'was $X, now $Y' deals.

4

Stack multiple discounts

Use the multi-step feature for sequential discounts (e.g. 20% off, then an additional 10% off). Note: stacked discounts do not add — 20% + 10% = 28% total, not 30%.

Discount Formulas Explained

Three discount calculations cover most real-world scenarios: Discount amount = Original Price × (Discount% ÷ 100). Sale price = Original Price × (1 − Discount% ÷ 100). Discount percentage = (Original − Sale Price) ÷ Original × 100. Example: A $80 jacket discounted 35%: Amount saved = $80 × 0.35 = $28. Sale price = $80 × 0.65 = $52.

Why Stacked Discounts Don't Add Up

A common misconception: a 20% discount followed by an additional 10% discount equals 30% off. It doesn't. The second discount applies to the already-reduced price. On a $100 item: first 20% off = $80. Then 10% off $80 = $72. Total saving: $28 = 28%, not 30%. The formula for combined sequential discounts: Combined% = 1 − (1 − D1)(1 − D2). For 20% and 10%: 1 − (0.8 × 0.9) = 1 − 0.72 = 28%. Retailers use this intentionally — "20% off + an extra 10% off" sounds better than "28% off."

Comparing Deals: Price per Unit Is What Matters

When comparing promotions across different sizes or quantities, the only valid comparison is price per unit (per gram, per ounce, per item). A "50% off" deal on a small pack may still be more expensive per unit than a regular-price bulk pack. Always divide the sale price by the quantity to find unit price before deciding which deal is genuinely better. Supermarket shelf labels in most US states now display unit prices — use them, or calculate them quickly with this tool.

Sources & Methodology

Calculations are based on the most current publicly available data from authoritative government and industry sources:

Frequently Asked Questions

Multiply the original price by the discount percentage, then subtract from the original. Example: 25% off $120 = $120 × 0.25 = $30 savings, so the sale price is $90.
Subtract the sale price from the original price to get the savings amount, then divide by the original price and multiply by 100. Example: ($120−$90)/$120 × 100 = 25% off.
A double discount (or stacked discount) applies two percentage discounts sequentially, not additively. 20% off then 10% off is NOT 30% off — it's 28% off total. Use our discount calculator for each step.
Multiply the original price by 0.20 to find the discount amount, then subtract. Example: 20% off $85 = $85 × 0.20 = $17 discount; sale price = $85 − $17 = $68. Shortcut: multiply the original price by 0.80 (1 − 0.20) to get the sale price directly. The same logic applies to any percentage.
Original price = sale price ÷ (1 − discount rate). If an item is on sale for $60 after a 25% discount: $60 ÷ (1 − 0.25) = $60 ÷ 0.75 = $80 original price. This is useful when you see a discounted price and want to verify or reverse-engineer what the original was.