Discount Calculator
Quickly calculate discount amounts and final prices, or reverse-calculate the discount rate from the payment amount.
Input Information
Result
Calculate discount amounts and final prices quickly!
When shopping or during promotions, it's often difficult to know the actual savings and final payment amount from a discount rate. Especially during sales or with complex discount conditions, predicting exact expenses can be challenging.
This calculator supports two modes: "Calculate Discount" mode shows savings and final payment from original price and discount rate, while "Reverse Discount Rate" mode calculates what percentage discount you received from the original price and actual payment.
A useful tool for business owners, shopping mall operators, marketers, and everyday consumers alike.
Term Glossary
- Discount Rate (%)
- A percentage representing how much of the original price is discounted. Discount amount is calculated by multiplying the original price by (discount rate ÷ 100).
- VAT
- An indirect tax applied at each stage of goods or services transactions. The actual payment may vary depending on whether the displayed price includes VAT.
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Choose mode
Use 'forward' for sale price from original; 'reverse' for original price from sale price.
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Enter price and rate
Forward: enter original price and discount %. Reverse: enter both original and sale price.
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Check results
Discount amount, final price, and rate appear. Reverse mode also shows the savings percentage.
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Practical use
For basket-level comparison, total saved ÷ total original price is the most accurate metric.
Example 1 — Forward: 30% off ₩200,000
Original ₩200,000 at 30% → discount ₩60,000, final ₩140,000. With 10% VAT added separately: ₩154,000.
Example 2 — Reverse: ₩154,000 purchased → what % off?
Bought at ₩140,000 from ₩200,000 original → saved ₩60,000 → rate = 30%. The reverse mode computes this automatically.
Discount Calculation Formulas
1. Discount Amount & Final Price Calculation
Subtract the discount amount from the original price to get the final price.
Discount Amount = Original Price × (Discount Rate ÷ 100)Final Price = Original Price - Discount AmountExample: 50,000 KRW item at 20% discount → Discount = 50,000 × 0.2 = 10,000 KRW → Final = 40,000 KRW
2. Reverse Discount Rate Formula
Divide the difference between the actual payment and original price by the original price to get the discount percentage.
Discount Rate(%) = (Original Price - Payment Amount) ÷ Original Price × 100Example: 50,000 KRW item purchased for 40,000 KRW → (50,000 - 40,000) ÷ 50,000 × 100 = 20% discount
💡 Key Discount Calculation Tips
1. Stacking discounts is not simple addition
"30% off then 20% additional discount" gives a 44% total discount effect (1 - 0.7 × 0.8 = 0.44). Simply adding to 50% overestimates the actual discount.
2. Application order affects the final price
When card discounts, coupons, and points accumulate, the final amount can vary by application order. Compare the most advantageous order in advance.
3. Check for price increases before discounts
Be aware of "fake discounts" where prices are raised before being discounted. Knowing regular prices helps you get real savings.
4. Use reverse mode to compare coupon efficiency
Use the reverse mode to determine which coupon among multiple options provides the most discount.
5. Check total savings for bulk purchases
Multiply the per-item discount by quantity to know total savings for budget management.
6. Calculate based on VAT-inclusive prices
Whether VAT is included can affect the final amount. Always verify if the displayed price includes VAT.
7. Check refund amounts in advance
Calculating the refund amount for discounted items helps prevent unexpected losses.
QCan I stack multiple discounts?
This calculator applies one discount at a time. In practice, multiple discounts (e.g., 30% off + 10% coupon) apply sequentially, yielding 0.70 × 0.90 = 0.63 (37% off), not 40%. For stacked discounts, enter the first result back as the new original price.
QHow do I find the original price from a sale price?
Original = sale price ÷ (1 − rate/100). Example: ₩77,000 at 30% off → ₩77,000 ÷ 0.70 = ₩110,000. The calculator's reverse mode does this automatically.
QCan I calculate tax-inclusive prices with this tool?
This calculator handles discount only (tax separate). For tax-inclusive: compute the discounted price here, then apply VAT (Korea: 10%). E.g., ₩100,000 at 20% off → ₩80,000, plus 10% VAT → ₩88,000 total.
QWhat about decimals when reversing the discount rate?
Reverse calculations often produce fractional won. Round to 1 won in practice. For bulk transactions, compute the discount amount from the original price instead of reversing, to avoid cumulative 1-won rounding errors.
QWhat's the difference between maximum and average discount?
Average discount rate and weighted-average (by price) can differ significantly. If expensive items have low discounts and cheap items high, the average rate looks generous but actual savings percentage is lower. Compare basket-level savings as total saved ÷ total original price.