Updated
Add GST or find the amount before tax
To add GST: tax = net amount × rate / 100, then gross = net + tax. To remove GST: net = gross / (1 + rate / 100), then tax = gross − net.
The presets are combined goods rates from the CBIC schedules, including the 2026 amendments. Other rate accepts a rate you already know, including zero. Services and conditional rates can differ; the list is not a product-rate finder.
Select CGST + SGST when you need two equal rate components. Otherwise the result shows the whole tax as IGST. You decide which treatment applies.
A worked example
For a net amount of ₹1,000 at 18%, GST is ₹180 and the gross amount is ₹1,180. The split is ₹90 CGST and ₹90 SGST. Removing 18% from ₹1,180 returns ₹1,000.
Before you use the result
Amounts use paise and round halves away from zero. Net plus tax always equals gross. If total GST contains an odd paise, the split assigns the extra paise to SGST so the displayed amounts reconcile; this is an arithmetic estimate, not a filing rule. Negative amounts are adjustments. Maximum input: ₹1 lakh crore. This tool does not determine product classification, registration, exemptions, input tax credits or cess.
Source notes
CBIC Notification 09/2025: goods tax schedules · Updated
Exact schedule headings: “Schedule I – 2.5%”, “Schedule II – 9 %”, “Schedule III– 20%”, “Schedule IV– 1.5%”, “Schedule V – 0.125%”, “Schedule VI – 0.75%”. These are central-tax rates. Doubling each for total GST gives the selectable goods rates 5%, 18%, 40%, 3%, 0.25% and 1.5%.
CBIC Notification 19/2025: removal of Schedule VII · Updated
Exact line: “the Schedule VII – 14%, and the entries relating thereto shall be omitted.” Effective date excerpt: “1st day of February, 2026”. This removes the former 28% combined goods schedule.
CBIC Notification 01/2026: current amendment · Updated
Exact excerpts: “in Schedule I – 2.5%” and “In Schedule III – 20%”. The latest central-tax rate amendment listed by CBIC on 2026-10-04 changes tariff entries and retains those schedule rates. This calculator does not classify products or apply exemptions, conditions or cess.
Cite this page
ToolOctopus. “GST calculator.” Updated 2026-10-04. https://tooloctopus.com/gst-calculator.
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