Phần hướng dẫn bên dưới chưa có bằng tiếng Việt nên được hiển thị bằng tiếng Anh. Bản thân máy tính đã được dịch đầy đủ.
Cách sử dụng máy tính này
- Enter the original price.
- Choose a percentage discount or a fixed amount off, and enter it.
- Optionally add an additional percentage discount applied after the first one.
Công thức
Stacked discounts multiply rather than add: 25% off followed by 10% off is 32.5% off in total, not 35%.
Sale price = price × (1 − d₁) × (1 − d₂)
Total discount = 1 − (1 − d₁)(1 − d₂)
Example
- $80 item at 25% off: 80 × 0.75 = $60.
- An extra 10% off: 60 × 0.90 = $54.
- You save $26, which is 32.5% off the original price.
Câu hỏi thường gặp
Is 20% + 20% off the same as 40% off?
No. Two successive 20% discounts equal 36% off (1 − 0.8 × 0.8), because the second discount applies to the already-reduced price.
Is sales tax applied before or after the discount?
In most places, tax is calculated on the discounted price. Use the sales tax calculator on the final price.
How do I find the discount percentage from two prices?
Divide the amount saved by the original price. For example, $60 instead of $80 is 20 ÷ 80 = 25% off. The percentage calculator can also do this.