01
How GST is worked out
Adding GST: GST = amount × rate ÷ 100, and total = amount + GST. Removing GST from an inclusive price: base = amount × 100 ÷ (100 + rate).
Free tool
GST calculator: add GST, or extract it from an inclusive price.
Enter an amount and a GST rate. See the GST, the CGST + SGST split for same-state sales or IGST for other-state sales, and the final total. Nothing you type leaves your browser.
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- Amount before GST
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- CGST
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- SGST
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- IGST
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- Total GST
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- Total
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Clear and practical
How GST is worked out
Adding GST: GST = amount × rate ÷ 100, and total = amount + GST. Removing GST from an inclusive price: base = amount × 100 ÷ (100 + rate).
02
How to extract GST from an inclusive price
Say ₹1,180 already includes 18% GST. The price before GST is 1,180 × 100 ÷ 118 = ₹1,000, and the GST inside it is ₹180: CGST ₹90 + SGST ₹90 in the same state, or IGST ₹180 to another state. Choose "Remove GST (inclusive)" above to do this for any amount.
03
GST rates changed in 2025
From 22 September 2025 most goods moved to 5% or 18%, with 40% for a few items. Some items still use 0%, 0.25% or 3%. Always check the current rate for your item on the CBIC website or with your CA.
FAQ
Questions and answers
Is this GST calculator free?
Yes, and it runs fully in your browser. We do not save what you type.
When do I use CGST + SGST vs IGST?
Same-state sale: split GST equally into CGST and SGST. Other-state sale: charge IGST.
How do I find the GST included in a bill amount?
GST included = amount × rate ÷ (100 + rate). For ₹1,180 at 18%: 1,180 × 18 ÷ 118 = ₹180.
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