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Guide · Calculators & Tools

GST Calculator — Add, Remove or Reverse GST

Enter any amount and slab rate to get the GST component, base price, total price and the CGST/SGST (intrastate) or IGST (interstate) split — instantly. Reverse mode extracts the base price from a GST-inclusive figure.

Written by
TaxClue Editorial Desk
Updated
18 August 2026
Reading time
3 min
Questions
12 answered
  • 5% · 12% · 18% · 28% slabs
  • CGST/SGST + IGST split
  • Add & reverse modes
Quick Answer

A GST calculator works out the GST amount and the gross/net price for a given slab rate. Enter the amount and pick the rate to see the GST component, the CGST/SGST split (intrastate) or IGST (interstate), and the final price in one step. The reverse mode extracts the base price from a GST-inclusive amount — e.g. ₹1,180 at 18% gives a base of ₹1,000 and ₹180 GST.

Free tool

GST Calculator

Choose Add GST to go from an exclusive amount to inclusive, or Remove GST to reverse a GST-inclusive figure back to its base. The tool splits the tax into CGST + SGST for intrastate supply and shows the full IGST for interstate supply.

Step by step

How the GST Calculator Works

  1. 1Enter amountType the value — exclusive (add) or inclusive (remove).
  2. 2Pick the slabSelect 5%, 12%, 18%, 28% or 3% gold.
  3. 3CalculateGST, base and total compute instantly.
  4. 4Read the splitSee CGST/SGST for intrastate or IGST for interstate.
The maths

GST Calculation Formula

CalculationFormulaExample at 18%
Add GST (exclusive → inclusive)GST = Amount × Rate/100; Total = Amount + GST₹1,000 × 0.18 = ₹180; Total ₹1,180
Remove GST (reverse — inclusive → exclusive)Base = Total ÷ (1 + Rate/100); GST = Total − Base₹1,180 ÷ 1.18 = ₹1,000; GST ₹180
Intrastate split (CGST + SGST)CGST = GST/2; SGST = GST/2CGST ₹90; SGST ₹90
Interstate (IGST)IGST = full GST amountIGST ₹180

Intrastate = supplier and place of supply in the same state (CGST+SGST). Interstate or imports = IGST at the full rate.

MRP is usually GST-inclusive

For consumer goods the printed MRP already includes GST, so use Remove GST to see the tax embedded in it. In B2B invoices, prices are normally quoted exclusive of GST — use Add GST there.

FY 2025-26

GST Slab Rates & Where They Apply

The rate you pick depends on the product/service HSN/SAC code. Common slabs at a glance:

RateTypical itemsCGST + SGSTIGST
0%Fresh produce, unbranded staples, education, health——
3%Gold, silver & jewellery1.5% + 1.5%3%
5%Essential food, footwear ≤₹1,000, transport2.5% + 2.5%5%
12%Processed food, apparel, business-class air6% + 6%12%
18%Most services, electronics, restaurants (non-AC standard)9% + 9%18%
28%Luxury goods, cars, aerated drinks, tobacco14% + 14%28%

Rates per the GST 2.0 slab structure effective FY 2025-26. Cess applies on some 28% luxury/sin goods over and above the rate.

CGST and SGST are always half each

For any intrastate supply the tax is split equally: 18% GST = 9% CGST + 9% SGST. CGST goes to the Centre and SGST to the State. For interstate supply or imports the entire amount is charged as IGST.

Not sure which slab or HSN code applies to your product?

Talk to a GST Expert →

Disclaimer: This guide is general information based on the law and notifications in force when it was last updated. It is not professional advice for your case — rates, thresholds and due dates change, so check the current position or speak to our CA team before you act on it.

People also ask

GST Calculator — Frequently Asked Questions

Short, direct answers to the 12 questions readers ask most on this topic.

At 18% GST: GST amount = ₹1,000 × 18/100 = ₹180. Total price with GST = ₹1,180. For intrastate supply this splits into CGST ₹90 + SGST ₹90; for interstate supply it is IGST ₹180. Enter the amount and rate in the calculator above to compute any figure instantly.

To add GST: GST = Amount × Rate/100 and Total = Amount + GST. To remove (reverse) GST: Base = Total ÷ (1 + Rate/100) and GST = Total − Base. CGST and SGST are each half of the GST amount for intrastate supply; IGST equals the full GST for interstate supply.

Reverse GST finds the base price (excluding GST) from a GST-inclusive amount. Formula: Base = inclusive price ÷ (1 + Rate/100). Example: ₹1,180 inclusive at 18% → Base = ₹1,180 ÷ 1.18 = ₹1,000, so GST = ₹180. Use the "Remove GST" mode in the calculator.

Divide the GST-inclusive total by (1 + rate/100). For 18%, divide by 1.18; for 12%, by 1.12; for 5%, by 1.05. The result is the base price, and the difference between the total and the base is the GST embedded in it.

For intrastate (same-state) supply, GST is split equally between CGST (Central) and SGST (State). So 18% GST = 9% CGST + 9% SGST. CGST goes to the central government and SGST to the state government.

IGST applies to interstate supplies (supplier and place of supply in different states) and to imports. It is charged at the full rate — 18% IGST instead of 9% CGST + 9% SGST. The recipient can still claim it as Input Tax Credit if registered.

The main GST rates are 0%, 5%, 12%, 18% and 28%, with a special 3% rate on gold, silver and jewellery and 0.25% on rough diamonds. Most services and electronics fall at 18%; essentials at 5%; luxury and sin goods at 28% (some with additional cess).

It depends on the HSN code of the product or the SAC code of the service. Broadly: essentials 5%, processed food and apparel 12%, most services and electronics 18%, luxury goods 28%, and gold 3%. Look up the exact rate using our HSN/SAC code guide.

Gold and jewellery attract 3% GST (1.5% CGST + 1.5% SGST intrastate, or 3% IGST interstate). Making charges on jewellery are taxed at 5% separately. Select the "3% (Gold)" option in the calculator to compute it.

For most consumer goods the printed MRP is GST-inclusive — the GST on the bill is already inside the MRP. To find the tax component, use the reverse (Remove GST) mode. In B2B transactions, prices are usually quoted exclusive of GST, with tax added on the invoice.

Yes. The TaxClue GST calculator is completely free, works in the browser, needs no sign-up, and computes add, remove and CGST/SGST/IGST splits instantly for all slab rates.

Yes. The calculator shows both: the CGST + SGST split for intrastate supply and the equivalent single IGST amount for interstate supply, for whatever amount and rate you enter.