Run a conservative scenario before relying on the headline result.
GST Calculator
Add or remove GST from a transaction value. Adjust the assumptions, inspect the chart and read the complete guide below.
02 Your projection
GST amount₹18,000Updates instantly as you edit
Total invested / base₹1.00 L
Growth / cost₹18,000
Inclusive amount₹1.18 L
Projection journeyHover to inspect a year
Confirm the applicable GST rate and input-tax treatment.
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Five smart nudges
Use the result with context.
Review the assumptions after any major change in income, rates or goals.
Keep emergency money separate from long-term investments.
Account for taxes, charges and inflation when comparing options.
Use this estimate to ask better questions, not as a return promise.
Understanding GST in India
Editorially reviewed 12 July 2026 · Rules and assumptions can change
Adding GST to a base value
For a taxable value of ₹1,00,000 at 18%, GST is ₹18,000 and invoice value ₹1,18,000. For an intra-state supply this may be split into CGST and SGST; an inter-state supply generally uses IGST. The arithmetic is simple, but place of supply and classification determine the correct tax structure.
Do not select 18% merely because it is common. HSN/SAC classification, exemptions, composition rules and notifications determine the applicable rate.
Removing GST from an inclusive price
If ₹1,18,000 already includes 18% GST, the base is ₹1,18,000/1.18 = ₹1,00,000 and tax is ₹18,000. Multiplying the inclusive price by 18% would incorrectly produce ₹21,240. The denominator method is essential whenever price is tax-inclusive.
Discount timing and invoice terms can change taxable value. Round and report according to invoice and return rules, not merely the display rounding here.
Input tax credit is not the same as tax amount
A registered recipient’s eligible input tax credit depends on business use, possession of valid documents, supplier reporting, receipt of supply, payment and blocked-credit provisions. The calculator only separates base and GST; it cannot determine credit eligibility or net cash liability.
Reverse charge, exports, zero-rated supplies, e-commerce and mixed supplies need specific analysis. Consult official CBIC/GST Council material or a tax professional.
GST calculation checklist
Confirm whether the entered amount is exclusive or inclusive, identify HSN/SAC and current rate, determine place and time of supply, and split CGST/SGST or IGST correctly. Verify cess where applicable.
Preserve invoice and registration details and reconcile returns. The output is invoice arithmetic, not a GST-compliance determination.
Official sources used for this guide
Rates, thresholds and rules can change after the review date. Check the linked authority and the provider’s current documents before acting.
GST calculator FAQs
How do I remove 18% GST from an inclusive price?
Divide the inclusive value by 1.18 for the base, then subtract the base from the total.
Is 18% the default GST rate?
No. The rate follows classification and current notifications.
When is GST split into CGST and SGST?
Generally for an intra-state supply; place-of-supply rules determine treatment.
Does displayed GST equal available input credit?
No. Credit eligibility has statutory and documentation conditions.
Does this calculator file GST returns?
No. It performs amount arithmetic only.