GST Calculator
IndiaAdd GST to a base price, back it out of an invoice, or net off input tax credit — with the CGST + SGST or IGST split.
Your invoice
CGST + SGST, each half the rate.
Results update live — calculations run in your browser, no signup.
₹1,800
On a ₹10,000 base — 15.3% of the ₹11,800 invoice
How the ₹11,800 invoice breaks down
Intra-state supply — CGST 9.0% + SGST 9.0% = ₹900 + ₹900.
Indicative at the current notified 18.0% slab — confirm the rate for your specific good or service.
How the invoice breaks down
Business perspective
Where each rupee of the invoice lands.
The GST you collect is held for the government — it is never your income. You remit it (less any input tax credit) when you file.
Every ₹100 the customer pays
Of the invoice total, this is your base vs the GST that goes to the government.
You keep
₹84.75
To government
₹15.25
GST breakup at 18.0%
CGST
9.0%
₹900
SGST
9.0%
₹900
Total GST
18.0%
₹1,800
Supply type
Which way are you computing?
Add GST on a base, or remove it from a tax-inclusive invoice — same 18.0% rate.
The total tax is ₹1,800 whichever way you compute, and whichever supply type you pick — split equally into CGST + SGST. Only the framing and the split change.
Reverse GST — strip the tax out of ₹11,800
When a quoted price already includes GST, this is the base hiding inside it.
Invoice (incl. GST)
₹11,800
Base (excl. GST)
₹10,000
GST inside
₹1,800
base = invoice ÷ (1 + rate) = ₹11,800 ÷ 1.18 = ₹10,000. The GST is the remainder.
Input tax credit — net GST payable
Output GST you collect, minus the GST you already paid on purchases.
Output GST (on sales)
₹1,800
collected from the customer
Input GST / ITC
−₹900
credit for tax paid on inputs
Net GST payable
₹900
remitted to the government
Net payable = output GST − input tax credit, floored at zero (a surplus carries forward, it is not refunded here). This illustrates one transaction; your real ITC position depends on supplier compliance and the items you can claim against.
The same ₹10,000 base across every slab
How the GST and invoice total move as you step through the standard rates.
Each row applies one standard GST slab to the same ₹10,000 base. Your selected 18.0% slab is highlighted. Slabs and item classifications change — check the current notified rate for your specific good or service.
What happens to ₹1.00 L of sales at 18.0%
On a ₹1.00 L base, what you keep vs what you collect for the government.
Your base
what you keep
GST collected
for the govt
Customer pays
invoice total
You bill ₹1.18 L, keep ₹1.00 L as your base, and hold ₹18,000 of GST to remit (less any input tax credit).
GST on different base amounts at 18.0%
A ready reckoner for the 18.0% slab, with the intra-state CGST/SGST split.
| Base amount | GST | CGST / SGST | Invoice total |
|---|---|---|---|
| ₹1,000 | ₹180 | ₹90 each | ₹1,180 |
| ₹5,000 | ₹900 | ₹450 each | ₹5,900 |
| ₹10,000 | ₹1,800 | ₹900 each | ₹11,800 |
| ₹25,000 | ₹4,500 | ₹2,250 each | ₹29,500 |
| ₹50,000 | ₹9,000 | ₹4,500 each | ₹59,000 |
| ₹1.00 L | ₹18,000 | ₹9,000 each | ₹1.18 L |
| ₹5.00 L | ₹90,000 | ₹45,000 each | ₹5.90 L |
CGST + SGST vs IGST on ₹10,000
Same total at every slab — intra-state splits it; inter-state charges one IGST.
| Slab | CGST | SGST | IGST | Total GST |
|---|---|---|---|---|
| Exempt (0%) | ₹0 | ₹0 | ₹0 | ₹0 |
| 3% | ₹150 | ₹150 | ₹300 | ₹300 |
| 5% | ₹250 | ₹250 | ₹500 | ₹500 |
| 12% | ₹600 | ₹600 | ₹1,200 | ₹1,200 |
What each slab usually covers
Worked example — a ₹10,000 service at 18.0%
A consultant, a commercial rent, or any taxable service invoice reads exactly like this.
The tenant or client pays ₹11,800; you retain ₹10,000 and remit ₹1,800 of GST. If they are GST-registered, that ₹1,800 becomes their input tax credit.
- GST is 15.3% of the ₹11,800 invoice the customer pays.
- Splits into ₹900 CGST + ₹900 SGST.
- You keep ₹10,000; ₹1,800 is held for the government.
More insights
On a base of ₹10,000, a 18.0% GST adds ₹1,800, taking the invoice to ₹11,800. GST is 15.3% of the invoice total. As an intra-state supply it splits into ₹900 CGST + ₹900 SGST.
Key takeaways
- Base (taxable) value: ₹10,000
- GST at 18.0%: ₹1,800
- Invoice total: ₹11,800
- CGST + SGST: ₹900 + ₹900
- GST as a share of the invoice: 15.3%
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Your invoice: ₹10,000 base + ₹1,800 GST = ₹11,800 total.
Put this tax in context
From GST on a bill to income tax, TDS and capital gains — plan the whole picture.
GST is computed as base × rate when adding, and invoice ÷ (1 + rate) when removing — the same arithmetic an invoice uses. For an intra-state supply the tax divides equally into CGST and SGST; for an inter-state supply it is a single IGST at the full rate, and the total tax is identical either way. The input-tax-credit summary nets your output GST against the input GST you enter — it illustrates one transaction, not your full ITC position. GST rates, slabs and item classifications are set by the GST Council and change from time to time — treat these figures as a quick estimate to verify against the current notified rate, not formal tax advice.
How GST is calculated
GST = base × r · invoice = base + GST
- base
- taxable value (price before GST)
- r
- GST rate as a fraction = rate% ÷ 100
- GST
- tax amount (split CGST + SGST, or one IGST)
- invoice
- tax-inclusive total the customer pays
Worked example
Your inputs — a ₹10,000 base at 18.0%: the GST is base × r = ₹10,000 × 0.18 = ₹1,800, split equally into ₹900 CGST + ₹900 SGST, taking the invoice to ₹10,000 + ₹1,800 = ₹11,800.
Indicative, at the current notified slab rate — confirm the rate for your specific good or service.
GST questions
GST (Goods and Services Tax) is an indirect tax levied on the supply of goods and services in India. It replaced a host of older taxes like VAT, service tax and excise with a single rate applied at each stage of the supply chain.
Adding GST starts from a net (pre-tax) price and adds the tax on top to get the gross price. Removing GST starts from a gross (tax-inclusive) price and backs out the tax to reveal the net price — useful when a quoted price already includes GST.
For a supply within the same state (intra-state), GST splits equally into CGST (collected by the centre) and SGST (collected by the state). For a supply across states (inter-state), it is a single IGST charged at the full rate instead. This tool lets you choose either, and the total tax is identical — only the split differs.
Input tax credit (ITC) lets a registered business offset the GST it paid on purchases against the GST it collects on sales, so tax is effectively paid only on the value it adds. ITC is broadly available on business inputs but is blocked on certain items — the GST Summary mode shows output GST minus your input credit to estimate net GST payable.
Divide the gross (tax-inclusive) price by (1 + rate). At 18%, that means dividing by 1.18 to find the net price; the difference is the GST. This is the reverse of adding GST, and is the right way to strip tax out of a quoted all-inclusive figure.
The complete guide to GST
What GST is and why it exists
GST (Goods and Services Tax) is a single indirect tax on the supply of goods and services in India, charged at standard slabs of 3%, 5%, 12%, 18% and 28%. It replaced a tangle of older taxes — VAT, service tax, excise and more — with one tax applied at each stage of the supply chain. Because registered businesses can claim credit for the tax paid on their inputs, GST effectively falls only on the value each link adds.
Adding GST vs removing GST
Adding GST starts from a base (pre-tax) price and adds tax on top: GST = base × rate, and the invoice is base + GST. Removing GST does the reverse — it strips the tax out of a price that already includes it: base = invoice ÷ (1 + rate), and GST is the difference. On a ₹10,000 base at 18.0%, the GST is ₹1,800 and the invoice is ₹11,800. Always check whether a quoted price is exclusive or inclusive before you compare two figures.
CGST, SGST and IGST
For a supply within one state (intra-state), GST divides equally into CGST, collected by the central government, and SGST, collected by the state — here ₹900 each. For a supply across state lines (inter-state), it is instead a single IGST charged at the full rate of 18.0%, collected by the centre and apportioned to the destination state. The total tax is the same; only the heads it is booked under differ.
Which slab applies
Most services and a broad range of goods sit at 18%, the standard slab. Essentials are taxed at 5%, mid-tier goods at 12%, and luxury or demerit goods — cars, air conditioners, tobacco — at 28%, sometimes with an additional compensation cess. A few items (gold, rough diamonds) attract 3%, and many basic foods are exempt. Classifications are notified by the GST Council and revised periodically, so confirm the current rate for your specific item.
Input tax credit and net GST payable
Input tax credit lets a registered business offset the GST it paid on purchases against the GST it collects on sales, so tax is paid only on the value it adds. The GST Summary mode subtracts your input GST from the output GST to estimate the net GST payable — here ₹900 on output of ₹1,800 less ₹900 of credit. ITC is broadly available on business inputs but blocked on certain items, and it depends on supplier compliance. This calculator shows the GST on a single transaction, not your full return.
A note on accuracy
Every figure here is derived from the same base × rate (or invoice ÷ (1 + rate)) arithmetic that an invoice uses, with the CGST/SGST/IGST split following from it. Treat the numbers as a planning estimate and confirm specifics with a tax professional; GST rules change and this is not formal advice.