Discount Calculator — Sale, Voucher, VAT

When to use this tool

• Online shopping: compute the true price after a 50% sale + 10% voucher — see if it's really a deal.
• Retail promos: shop owners pricing for a sale, knowing margin after VAT.
• Price negotiations: complex deals with 2-3 layered discounts — know the net.
• Service invoicing: contract discount 15% + voucher 5%, plus VAT 8% — final amount due.

How stacked discounts work

When applying 2 discounts, DO NOT add the percentages — apply them sequentially:

• Original price 1,000,000đ, 30% off, then extra 10% off:
• Step 1: 1,000,000 × 70% = 700,000đ
• Step 2: 700,000 × 90% = 630,000đ
• Real total discount: 37% (not 40%)

This tool computes it correctly — matching how Shopee, Lazada, and most e-commerce platforms apply voucher stacking.

Where does VAT fit in?

By Vietnamese law, VAT is added after the discount:

• Original → discount 30% → sale price → add VAT 8% → final customer price.
• Most restaurant and retail bills already include VAT — only add VAT% if the displayed price doesn't include it.