Free GST calculator
Pick add or remove, enter the amount, choose the GST rate and the supply type — and get the full invoice breakup with the working shown.
Everyday invoice maths, not tax advice. This tool adds GST to a quote or pulls it out of an MRP. It is not tax advice; the rate depends on the HSN or SAC code of the item, so check the rate for your item on the CBIC rate schedule or with your CA.
Example figures are filled in. Replace them with your own numbers.
GST = 10,000 × 18 ÷ 100 = 1,800.
Total = 10,000 + 1,800 = 11,800.
Within one state the GST splits equally: ₹900 CGST + ₹900 SGST.
Every figure is rounded to the paisa; the full figure is used until the final rounding, so the working above always reproduces the answer.
Select Calculate to keep up to five checks while this page is open.
Understand the result
GST is charged on the price before tax, so every GST question is one of two: add the tax to a base price when you raise an invoice, or pull the tax out of a total that already includes it, as an MRP does. This calculator does both, at the current Indian GST rates, and splits the tax into CGST + SGST for a sale within one state or IGST for a sale between states — with the working shown, so you can check every number instead of trusting a black box.
A quote before tax needs GST added: base × rate ÷ 100. An MRP already includes it, so the tax has to be pulled out: total × 100 ÷ (100 + rate). The two directions use different formulas — mixing them up is the most common GST mistake.
The rate always applies to the base price, never to the total. That is why removing GST means dividing by (1 + rate ÷ 100) instead of multiplying the total by the rate — multiplying taxes the tax as well.
Within one state the GST is split equally into CGST and SGST; between states the whole amount is charged as IGST. The total never changes — only which government receives which share.
How it works
Pick the direction first — the labels change to match it — then enter the amount, the rate and the supply type.
Adding GST is for a base price — a quote or an invoice before tax. Removing GST is for a total that already includes it, like an MRP or a vendor's bill.
Type the amount in rupees and pick the GST rate for the item. The rate list carries the current GST 2.0 rates; use Custom rate for anything else.
A sale within one state splits the GST into CGST + SGST, half each. A sale between states charges the whole amount as IGST. The total is the same either way.
The answer appears as you type — base, GST, split and total — with the step-by-step working underneath so you can check every number.
The calculation, explained
Two formulas, one idea: GST is always charged on the price before tax. Adding GST: GST = base × rate ÷ 100, and total = base + GST. Removing GST: base = total × 100 ÷ (100 + rate), and GST = total − base. Within one state the GST is split equally into CGST and SGST; between states the whole amount is charged as IGST. Every figure is rounded to the paisa.
Worked examples
One example for each everyday case. Select any example to load it into the calculator and check the working for yourself.
10,000 × 18 ÷ 100 = 1,800, so the total is 10,000 + 1,800 = 11,800. Within one state that ₹1,800 splits into ₹900 CGST and ₹900 SGST.
₹10,000 + 18% GST = ₹11,800 (GST ₹1,800)
11,800 × 100 ÷ 118 = 10,000, so the GST inside is 11,800 − 10,000 = 1,800. Multiplying the total by 18% would wrongly give ₹2,124.
₹11,800 incl. 18% GST → base ₹10,000 (GST ₹1,800)
1,00,000 × 3 ÷ 100 = 3,000, so the total is 1,03,000. Gold and jewellery carry the special 3% rate, not the standard 18%.
₹1,00,000 + 3% GST = ₹1,03,000 (GST ₹3,000)
2,000 × 5 ÷ 100 = 100, so the total is 2,100. A restaurant bill or a service at 5% works the same way — and between states the ₹100 is charged in full as IGST.
₹2,000 + 5% GST = ₹2,100 (GST ₹100)
GST rates in India after GST 2.0
The rates in force for new supplies from 22 September 2025, after the 56th GST Council meeting. The old 12% and 28% slabs were abolished for new supplies — a bill dated before 22 September 2025 may still correctly show them.
| Rate | Typically applies to | Example |
|---|---|---|
| 0% | Exempt essentials | Fresh milk, vegetables, cereals, healthcare and education services |
| 5% | Merit rate — everyday goods and services | Restaurants, household consumables, clothing and footwear up to ₹2,500 |
| 18% | Standard rate — most goods and services | Small cars, air conditioners, most services such as telecom, banking and IT |
| 40% | Demerit rate — luxury and sin goods | Large cars and SUVs, pan masala, tobacco products, aerated sugary drinks |
| 3% | Special rate — gold, silver and jewellery | Gold ornaments and jewellery on the transaction value |
| 0.25% | Special rate — rough precious stones | Rough diamonds and precious stones |
| 1.5% | Special rate — cut and polished diamonds | Cut and polished diamonds |
The rate always depends on the item: the same product can sit in a different slab under a different HSN code, so confirm the rate for your exact item on the CBIC rate schedule before invoicing.
Common mistakes
The formulas are short, but four readings trip people up. Each one can turn a right method into a wrong invoice.
Removing GST is not total × rate ÷ 100. On ₹11,800 at 18% that gives ₹2,124 — ₹324 too much. Divide instead: 11,800 × 100 ÷ 118 = ₹10,000 base, so the GST is ₹1,800.
The 12% and 28% slabs were abolished for new supplies on 22 September 2025. Most 12% items moved to 5% and most 28% items to 18%. Only a bill dated before that date may still correctly show them.
CGST + SGST is for a sale within one state; IGST is for a sale between states. The split changes, but the total never does — 18% on ₹10,000 is ₹1,800 either way.
Round each figure to the paisa only at the end. Rounding the base first and then subtracting can leave the GST a paisa out — and a paisa out on every line adds up across an invoice.
Your questions, answered
Multiply the base price by the rate and divide by 100, then add it to the base. At 18% on ₹10,000: 10,000 × 18 ÷ 100 = ₹1,800 GST, so the total is 10,000 + 1,800 = ₹11,800. Use the 'Add GST' mode on this page and the working is shown for you.
Divide the total by (1 + rate ÷ 100). At 18% on ₹11,800: 11,800 ÷ 1.18 = ₹10,000 base, so the GST inside is 11,800 − 10,000 = ₹1,800. Never multiply the total by the rate — ₹11,800 × 18% = ₹2,124, which is ₹324 too much.
Since 22 September 2025, under GST 2.0, the main slabs are 0% (exempt essentials), 5% (merit rate) and 18% (standard rate), with a 40% demerit rate for luxury and sin goods. Special rates continue: 3% on gold, silver and jewellery, 0.25% on rough precious stones and 1.5% on cut and polished diamonds. The old 12% and 28% slabs were abolished for new supplies. The rates come from CBIC Notification 9/2025-Central Tax (Rate), dated 17 September 2025.
CGST and SGST apply when buyer and seller are in the same state: the GST is split equally, half CGST (Centre) and half SGST (State). IGST applies when the supply crosses a state border: the whole GST is charged as IGST. The total is identical either way — 18% on ₹10,000 is ₹1,800 as ₹900 + ₹900 or as ₹1,800 of IGST.
Gold, silver and jewellery carry a special 3% rate on the transaction value. On ₹1,00,000 of gold: 1,00,000 × 3 ÷ 100 = ₹3,000 GST, so the total is ₹1,03,000. Making charges on jewellery are also taxed — check the invoice breakup or ask your jeweller for the HSN-wise split.
Because the rate applies to the base price, not to the total. The total already contains the tax, so multiplying it by 18% taxes the tax as well. On ₹11,800 at 18% that gives ₹2,124 instead of the correct ₹1,800. The right move is to divide: 11,800 × 100 ÷ 118 = ₹10,000 base, then subtract.
Generally, a business must register once its annual turnover crosses ₹40 lakh for goods or ₹20 lakh for services (₹10 lakh in special-category states). Registration is also compulsory for inter-state supplies and e-commerce sellers regardless of turnover. These are the usual thresholds — confirm your position on gst.gov.in or with a CA before acting.
They were abolished for new supplies from 22 September 2025, when GST 2.0 merged the old four-slab structure into 5% and 18% plus a 40% demerit rate. Most items that sat at 12% moved to 5%, and most at 28% moved to 18%. A bill dated before 22 September 2025 may still correctly show 12% or 28%.
No. Every calculation runs entirely on this page — nothing is sent to a server, nothing is stored, and reloading the page clears your recent checks.
This page uses the two standard GST formulas: adding GST, GST = base × rate ÷ 100 and total = base + GST; removing GST, base = total × 100 ÷ (100 + rate) and GST = total − base. Within one state the GST is split equally into CGST and SGST; between states the whole amount is IGST. Every figure is rounded to the paisa, and the full figure is used until the final rounding, so the working you see always reproduces the answer shown.
Rates checked 11 November 2026 against the GST 2.0 structure in force from 22 September 2025: the main slabs are 0%, 5% and 18% with a 40% demerit rate, and the special rates are 3% on gold, silver and jewellery, 0.25% on rough precious stones and 1.5% on cut and polished diamonds, per CBIC Notification 9/2025-Central Tax (Rate), dated 17 September 2025, following the 56th GST Council meeting. Cross-checked against the ranking GST calculators: 18% on ₹10,000 is ₹1,800, total ₹11,800, on primoerp.com and calxo.in, and the same ₹11,800 reverse case gives a ₹10,000 base on taxgarden.in. Compensation cess is not calculated here — it was withdrawn for most goods from 22 September 2025. Confirm the rate for your exact item on the CBIC rate schedule before invoicing.
Try different numbers — or run the same check with the related tools for your other plans.
