GST calculator online (India)
Add GST to a base amount, or remove GST from an inclusive amount.
Examples
Add 18% GST to 1,000 → GST 180, total 1,180.
Remove 18% GST from 1,180 → base 1,000, GST 180.
FAQ
How to add GST to a price?
Total = base × (1 + rate/100).
How to remove GST from an inclusive price?
Base = total ÷ (1 + rate/100).
What is a GST calculator?
A GST calculator helps you convert between base price, GST amount, and total price. In India, prices are commonly shown either as exclusive (GST added on top) or inclusive (GST already included). This tool supports both so you can calculate quickly and avoid billing mistakes.
What is GST in India?
GST (Goods and Services Tax) is an indirect tax used in India. On invoices you may see GST split into components like CGST + SGST (intra-state) or IGST (inter-state). This calculator computes the overall GST amount from the base/total; you can split it later as per invoice rules.
GST inclusive vs GST exclusive price
In real life, confusion usually comes from whether the price is inclusive or exclusive of GST: if you see a base price and GST is added at checkout or on an invoice line item, that’s exclusive. If you see a final price (MRP or “total”) where GST is already embedded, that’s inclusive. This page supports both scenarios so you can move between base, GST, and total without manual mistakes.
How to calculate GST online
If you have a base amount and want the total price, you add GST. If you have the final bill amount and want the original base amount, you remove GST. This tool supports the most common GST slabs: 0%, 5%, 12%, 18%, and 28%.
Step-by-step
1) Pick the correct GST rate: 0/5/12/18/28 (based on your invoice/product category).
2) Choose price type: base (exclusive) or total (inclusive).
3) Select mode: Add GST (exclusive → inclusive) or Remove GST (inclusive → exclusive).
4) Enter the amount and read base, GST and total.
Common GST slabs (quick reference)
0% · 5% · 12% · 18% · 28% — the applicable rate depends on the good/service category. Use the correct slab from your invoice/product category for accurate results.
GST calculation formula
Add GST: total = base × (1 + rate/100)
Remove GST: base = total ÷ (1 + rate/100)
GST amount = total − base
Example GST calculation
Base ₹1000 @ 18% GST
GST = 1000 × 18% = ₹180, Total = ₹1180
Common mistakes (avoid them)
The most common manual error is removing GST by doing GST = total × rate%. That’s incorrect for inclusive prices because the GST is already embedded in the total. Use the “Remove GST” mode which divides by $(1 + rate/100)$ first.
When should you use this tool?
Use it when creating invoices/quotations, checking GST-inclusive totals, verifying MRP vs base price, or quickly auditing a bill. It’s also useful when you know only the total and need the base amount for bookkeeping.
Why use this GST calculator online?
It reduces calculation errors, especially when removing GST from an inclusive price (this is where most manual mistakes happen). Use it for invoicing, budgeting, and quick checks when you see GST-inclusive MRP or totals.
More FAQs
How to calculate GST amount from base? Multiply base by rate% to get GST, then add to base.
How to calculate base price from total? Divide total by (1 + rate/100).
Which decimals should I use? Use 2 decimals for most billing; use more decimals for internal checks.