How to Calculate Percentage Discounts & the Final Price

Stores love showing “30% off” — but what do you actually pay? Here is how to calculate it.

Discount Formulas

Discount = original price × (discount % ÷ 100)

Final price = original price − discount

Example

A shirt costs 1,299 THB with 30% off:

• Discount = 1,299 × 0.30 = 389.70 THB
• Final price = 1,299 − 389.70 = 909.30 THB

Stacked Discounts

20% off then another 10% off the remaining price — not a flat 30%.

Example: 1,000 THB → 20% off = 800 → 10% off 800 = 80 → pay 720 THB (flat 30% would be 700).

“Buy X Get Y” Deals

• Buy 1 get 1 free → average 50% off
• Buy 2 get 25% off → only if you buy two
• Points programs → compare the real % first

Where It Applies

• Online shopping (Shopee/Lazada)
• Malls and convenience stores
• Restaurant promotions

Try the discount calculator to know the real price before you buy.