Most GST Excel sheets you can download were built before September 2025, and still offer 12% and 28% as everyday rates. The GST Council's reform from 22 September 2025 moved most 12% items to 5% and most 28% items to 18%, and set 40% for luxury and sin goods. This free sheet uses the current slabs, and does the two jobs people actually need: add GST to a price, or take GST out of a price that already includes it.
⬇ Download: GST calculator in Excel (.xlsx, free)What's in the sheet
- GST calculator tab: amount, rate (0, 3, 5, 18 or 40%), whether the amount is before GST or includes it, and whether the supply is within your state or to another state.
- It returns the value before GST, the GST, the total, and the split: CGST + SGST for a sale within the state, IGST for a sale to another state.
- Invoice lines tab: up to 20 items, each with its own rate, with per-line GST and the CGST / SGST / IGST totals for the whole bill.
The formulas
Adding GST: total = value × (1 + rate ÷ 100). At 18%, ₹10,000 becomes ₹11,800, and within the state that ₹1,800 is shown as ₹900 CGST and ₹900 SGST. To another state, the same ₹1,800 is a single IGST.
Removing GST from an inclusive price: value before GST = price ÷ (1 + rate ÷ 100). ₹11,800 including 18% GST is ₹10,000 plus ₹1,800 of GST. A common mistake is to take 18% of ₹11,800 (₹2,124), which overstates the tax.
Prefer it online? GST calculatorReverse GST calculator (take GST out)Read: the full GST slab list after the reformFrequently asked questions
- What is the formula to add 18% GST in Excel?
- =A2*1.18 gives the total including GST, and =A2*18% gives the GST alone. Within a state, split the GST into two halves for CGST and SGST.
- How do I remove GST from a total in Excel?
- =A2/(1+18%) gives the value before GST for an 18% rate; the GST is the total minus that value. Taking 18% of the total overstates it.
- What are the GST rates in 2026?
- After the GST Council's reform effective 22 September 2025, the main slabs are 0%, 5% and 18%, with 40% for luxury and sin goods and 3% for gold. Check your item's HSN code for its exact rate.
- When is IGST charged instead of CGST and SGST?
- IGST applies when goods or services are supplied from one state to another. Within the same state, the tax is split equally into CGST and SGST (or UTGST in a union territory).