Marks Calc

Calculate Sale Prices, Savings & Double Discounts

Free discount calculator with double discount support and GST. Calculate effective discount percentage, price after all discounts, and final price including tax. Perfect for Flipkart/Amazon sale shopping.

How It Works

Savings = Price × (D₁/100) + (Price - D₁) × (D₂/100); Effective = Savings/Price × 100

The first discount reduces the original price. The second discount (if any) applies to the already-discounted price, not the original. This means two 50% discounts do NOT make it free — they make it 75% off. The effective discount shows the combined percentage saved.

Quick Tips

Double Discount Trap
Two 50% off discounts = 75% off, NOT 100% off. The second discount applies to the already-reduced price.
GST on Discount
In India, GST is calculated on the post-discount price, not the MRP. A ₹1000 item at 20% off + 18% GST = ₹800 + ₹144 = ₹944.
Effective Rate
A 20% + 10% double discount = 28% effective discount (not 30%). Our calculator shows the real combined savings.
Student Discounts
Amazon Prime Student: 50% off. Apple Education: ~10% off. Spotify Student: 50% off. Always check for student deals before buying.

Step-by-Step Instructions

  1. 1Enter the original price of the item.
  2. 2Set the discount percentage (first discount).
  3. 3Add an additional discount if applicable (e.g., coupon code).
  4. 4Set GST rate if you want the final price including tax.

Frequently Asked Questions

How do I calculate 20% off?
Multiply the price by 0.20 to get the savings, then subtract from original price. For ₹5000 at 20% off: savings = ₹1000, final price = ₹4000.
What is effective discount?
Effective discount is the total percentage saved from the original price. With double discounts of 20% + 10%, you save ₹280 on ₹1000 = 28% effective discount (not 30%).
Is GST applied before or after discount?
After discount. GST is calculated on the discounted price. For example, ₹1000 item with 20% discount: GST applies to ₹800, not ₹1000.
How do I calculate price after discount and GST?
Apply discount first: Price × (1 - Discount%). Then add GST: Discounted Price × (1 + GST%). Our calculator does both steps automatically.