GST Calculator — Inclusive, Exclusive, CGST, SGST and IGST
Reviewed by Finin2min Editorial Desk · Last reviewed 4 September 2026
Calculate GST-exclusive or GST-inclusive values and split tax between CGST–SGST or IGST.
Calculate GST from taxable or inclusive value
Tax calculation
Taxable value
—
Invoice total
—
Component
Amount
Total GST
—
CGST
—
SGST / UTGST
—
IGST
—
Cess entered
—
How This Is Calculated
GST can be calculated two ways: adding GST to a base amount ("exclusive"), or extracting the embedded GST from a GST-inclusive total ("inclusive") using tax/(1+rate). For intra-state supplies, the GST amount splits equally into CGST and SGST; for inter-state supplies, the full amount is charged as IGST. Since the September 2025 rate rationalisation, the standard GST slabs in India are 5% and 18%, with a 40% slab for select luxury/sin goods and 0% for nil-rated essentials — the earlier 12% and 28% slabs no longer exist. Compensation cess now applies only to a small list of notified sin/tobacco goods.
Frequently Asked Questions
What is the difference between GST-inclusive and GST-exclusive amount?
▼
A GST-exclusive amount is the base price before tax is added — GST is calculated on top of it. A GST-inclusive amount already has tax built in, so the GST portion has to be extracted from the total using the formula: GST = total − total/(1+rate).
When do I charge CGST + SGST versus IGST?
▼
CGST (Central GST) and SGST (State GST) apply in equal halves for intra-state supplies, where the supplier and the place of supply are in the same state. IGST (Integrated GST) applies as a single tax for inter-state supplies, where the supplier and place of supply are in different states, or for imports/exports.
What are the common GST rate slabs in India?
▼
Following the September 2025 GST rate rationalisation, the standard slabs are 5% and 18%, with a 40% slab for select luxury and sin goods, plus 0% (nil-rated) for essentials. The earlier 12% and 28% slabs were removed — most 12% items moved to 5% and most 28% items moved to 18%. Compensation cess was scrapped except on a small list of notified sin/tobacco goods. The applicable rate depends on the HSN/SAC classification of the goods or service.
How do I calculate GST on an MRP that already includes tax?
▼
Since MRP is GST-inclusive, use the inclusive method: taxable value = MRP ÷ (1 + GST rate), and GST amount = MRP − taxable value. Switch the calculator to "inclusive" mode and enter the MRP as the amount.
Source and review trail
Use the current official instrument, portal or regulator publication before acting.
Inclusive/exclusive GST arithmetic can be automated; classification cannot. The correct rate comes from the Customs Tariff classification, full notification description, exclusions, conditions and supply date.
Use the calculator only after rate/classification is established. Keep invoice value, rate, intra-/inter-State treatment and rounding evidence with the transaction.
Input integrity
Use source documents rather than approximate memory.
Confirm period, units, tax regime/category and sign conventions.
Test zero, threshold and just-above-threshold cases where relevant.
Output interpretation
Separate arithmetic output from legal eligibility/classification.
Preserve assumptions and the official-source date.
Use the linked detailed guide for exceptions and evidence.
Reviewed 22 August 2026. Always test later amendments, corrigenda and portal implementation before a live filing or transaction.
Methodology, assumptions and sources
Scope: Computes GST amount and total price for both tax-inclusive and tax-exclusive scenarios, and splits the tax into CGST+SGST (intra-state) or IGST (inter-state), based on the applicable rate.
Calculation logic
Exclusive mode: GST amount = Base price × Rate ÷ 100; Total price = Base price + GST amount.
Inclusive mode: Base price = Total price × 100 ÷ (100 + Rate); GST amount = Total price − Base price.
Intra-state supply: split the computed GST amount equally into CGST and SGST (each at half the total rate); Inter-state supply: the full computed amount is IGST.
Inputs and assumptions
Whether a supply is intra-state (CGST+SGST) or inter-state (IGST) is determined by the place of supply relative to the supplier's registered location, per Sections 7-9 of the IGST Act — the user selects the correct scenario.
Rate entered should be the applicable GST rate for the specific goods/service per its HSN/SAC classification — the calculator applies whatever rate is entered, it does not look up the rate for a specific item.
Exclusions and edge cases
Does not itself classify goods/services into the correct HSN/SAC code or determine the applicable rate — use the HSN/SAC Finder for that.
Compensation cess (applicable to specific goods like tobacco, automobiles) is not included unless entered separately.
Review status: reviewed and approved by CA Nikhil Gupta on 5 July 2026; rate slabs updated 4 September 2026 for the September 2025 GST rationalisation (5%/18%/40%, 12% and 28% removed).
Guides on this topic
Background, worked examples and the rules behind these numbers.