Book a free consultation
Tell us what you need and an expert will reply within one business day.
Add or remove GST from any amount instantly, with the CGST/SGST or IGST split. Free, and no sign-up needed.
For quick reference only — always confirm the applicable GST rate for your specific goods or service.
Also try: Income Tax Calculator · Advance Tax Calculator
Whether you're invoicing a client, checking a supplier's bill, or just want to know how much GST is baked into a price, doing the maths by hand is easy to get wrong — especially when switching between adding and removing GST. This GST calculator India businesses can use does both instantly, and shows the CGST/SGST or IGST split so the breakdown matches what you'd see on an actual invoice.
Below the calculator, this page explains the formula it uses, how the reverse GST calculator mode works, what CGST, SGST, and IGST mean, and answers common questions about GST calculation. If you need help with GST registration, returns, or compliance rather than just a quick calculation, our GST compliance services cover that end to end.
A GST calculator adds or removes GST from an amount using the formula: GST amount = (amount × rate) / 100 to add GST, or GST amount = inclusive amount − [inclusive amount × 100 / (100 + rate)] to remove it. This online GST calculator does both instantly and splits the result into CGST/SGST or IGST.
"Add GST" starts from a base amount; "Remove GST" starts from an amount that already includes GST.
Type in the number — the result updates instantly as you type.
Pick the GST slab that applies, and whether the supply is within one state or between states.
See the taxable amount, the CGST/SGST or IGST split, and the total amount.
To add GST: multiply the base amount by the rate and divide by 100 to get the GST amount, then add it to the base amount for the total. To remove GST from an inclusive amount: divide the inclusive amount by (100 + rate) and multiply by 100 to get the base amount, then subtract that from the inclusive amount to get the GST portion.
CGST + SGST vs IGST: for a sale within one state, the rate splits evenly into CGST and SGST. For a sale between two states, the same total rate is charged as IGST instead. The total tax is identical either way.
| Slab | Typically used for |
|---|---|
| 0% | Goods and services specifically exempted |
| 5% | Essential and mass-consumption items |
| 12% | Standard-rated goods and services |
| 18% | Most goods and services (the default slab) |
| 28% | Luxury and select goods |
Rate slabs are revised by government notification from time to time, and the exact rate depends on the specific HSN/SAC classification. Confirm the current rate for your item before invoicing or filing.
A GST calculator applies the GST rate to an amount using a simple formula. To add GST to a base amount: GST amount = (base amount × rate) / 100, and the final amount is the base amount plus GST. To remove GST from an amount that already includes it: base amount = (inclusive amount × 100) / (100 + rate).
For a sale within the same state, GST is split equally into CGST (central) and SGST (state), each at half the total rate. For a sale between different states, the full rate is charged as IGST (integrated GST) instead. The total tax amount is the same either way — only how it's split differs.
Yes. This reverse GST calculator mode is built in — select "Remove GST" and enter the GST-inclusive amount, and it works backward to show the original (taxable) amount and the GST portion within it.
The rate slabs shown (0%, 5%, 12%, 18%, 28%) are the standard GST slabs, but the rate that applies to a specific product or service can change by government notification. Always confirm the current rate for your specific item before filing or invoicing — this tool calculates based on whichever rate you select, it doesn't look up rates for you.
This tool is for quickly working out a GST amount — it doesn't file returns or replace your GST records. For actual return filing, reconciliation, and compliance, see our GST return filing and GST compliance services.
This tool helps with a quick calculation. If you need GST registration, monthly or quarterly return filing, reconciliation, or a reply to a GST notice, Tax Care Hub handles that end to end.
Tell us what you need and an expert will reply within one business day.