Discount & Promotion Calculator

A discount changes the customer's effective price; the right calculation depends on the mechanic and whether the original price includes VAT. This tool normalises six different mechanics so the comparison — and the savings figure you advertise — stays apples-to-apples.

Effective discount per mechanic

Each mechanic maps to an effective percentage off the original:

Percentage: rate% | Fixed: amount ÷ price | BOGO (Buy N Get M): M ÷ (N + M) | Bundle: (Standalone − Bundle) ÷ Standalone | Volume: highest tier hit | Cashback: rate% returned (price still paid at checkout)

Worked example

A 100 SAR item with a 'Buy 2 Get 1 Free' promo, VAT-exclusive:

1. Cart of 3 units at 100 SAR each = 300 SAR standalone
2. BOGO effective rate = 1 ÷ (2 + 1) = 33.33%
3. Discount = 300 × 33.33% = 100 SAR (one free unit)
4. Price after discount = 200 SAR (net)
5. Plus 15% VAT = 30 SAR
6. Final price the customer pays = 230 SAR

Practical tips

• Inclusive VAT is the legal default on Saudi B2C stickers — discount the gross price, then back-derive VAT.
• Exclusive VAT fits B2B quotes — discount the net, add VAT after.
• Cashback isn't a discount at checkout — clarify this in the offer copy to avoid confusion.
• Volume tiers reward only the highest threshold the customer hits — for marginal volume rewards use bundle or graduated commission instead.
• BOGO works on the cart total — communicate it as 'save 33%' for clarity if the math is unfamiliar.