GST & VAT Calculator

One task, zero friction: calculate gst (cgst/sgst/igst) & vat, inclusive or exclusive, with slab presets. GST & VAT Calculator runs right in your browser as part of ToolsMonk's business tools lineup: no installs, no account, and nothing to configure before you start.

People reach for it most often when they need working out the tax-inclusive price to display when your cost is quoted net, extracting the tax already contained in a gross figure for bookkeeping, and splitting indian gst into cgst and sgst for an intra-state sale, or igst for inter-state. With nothing to install, an unexpected one-off job takes no longer to start than your regular routine.

It is built for getting a real result on the first visit: no learning curve, no account, and the wider ToolsMonk toolbox close at hand.

The GST and VAT Calculator works in both directions: it adds tax to a net amount, and it extracts the tax already contained in a gross one. For Indian GST it also splits the total into CGST and SGST for intra-state supplies, or shows it as IGST for inter-state.

The reverse direction is where most errors happen, and it is worth stating the correct method plainly. To find the net inside a tax-inclusive price you divide by one plus the rate, not subtract the rate. At 18 percent, a gross of 1,180 contains a net of 1,000, because 1,180 divided by 1.18 is 1,000. Subtracting 18 percent instead gives 967.60, an error of over 30, and the discrepancy grows with the rate. This mistake appears constantly in spreadsheets and quietly misstates both revenue and tax.

The Indian split confuses people because the total never changes. An intra-state supply, where buyer and seller are in the same state, divides the tax equally between the centre and the state: an 18 percent supply is 9 percent CGST plus 9 percent SGST. An inter-state supply is a single IGST at the full 18 percent. The customer pays the same either way; what differs is which government collects it and how the invoice must show it.

One thing the calculator deliberately cannot do is tell you which rate applies. That depends on HSN or SAC classification, the schedules change, and misclassification is a compliance matter rather than an arithmetic one. The tool applies whatever rate you supply, accurately; confirming the right rate is a job for the current official schedule or your accountant.

VAT works the same way arithmetically. It is a consumption tax applied as a percentage, and adding or extracting it uses identical maths. What differs between systems is everything around the number: registration thresholds, reduced and zero rates, exemptions, reverse charge, and the mechanics of reclaiming input tax. Use this for the calculation and your local rules for the rest.

Finally, whether you should display prices inclusive or exclusive of tax is usually a legal question rather than a stylistic one. Many jurisdictions require consumer-facing prices to include tax, while business-to-business quoting is conventionally exclusive. It is worth confirming the rule where you sell before deciding how to present your prices.