What is a GST calculator?
A GST calculator splits or adds Goods and Services Tax on a price. In India, common GST slabs are 5%, 12%, 18%, and 28% depending on the product or service category.
Choose whether your entered amount is GST-exclusive (tax added on top) or GST-inclusive (tax already embedded in the total). The tool shows base amount, GST component, and final total.
When do you need a GST calculator?
Invoices and MRP labels don't always spell out the tax split. A quick calculation helps vendors, freelancers, and buyers reconcile numbers.
- Add 18% GST to a quoted base price before raising an invoice.
- Extract base and tax from a GST-inclusive MRP or bill total.
- Compare net cost across slabs for planning—not for legal classification.
How does this GST calculator work?
GST exclusive: GST = base × rate / 100, total = base + GST. GST inclusive: base = total / (1 + rate/100), GST = total − base.
GST = Base × Rate / 100
Where –
| Base | Taxable value before GST |
|---|---|
| Rate | GST percentage (e.g. 18) |
Inclusive: Base = Total / (1 + Rate/100)
Worked example
A service quoted at ₹10,000 plus 18% GST: GST = ₹1,800, total invoice = ₹11,800. If the quote is ₹11,800 inclusive, the base is ₹10,000 and GST is still ₹1,800.
How to use this GST calculator
Select GST exclusive or inclusive, enter amount and GST rate, and read base, tax, and total. Sliders support common slab rates from 0% to 28%.
For GST on trading charges, see the brokerage calculator. When tax applies to payments rather than goods, check the TDS calculator.
What this calculator does not include
CGST/SGST/IGST split, cess, reverse charge, input tax credit, HSN classification, and rounding rules on tax invoices are not modeled. Use this for arithmetic only—not filing returns.
Frequently asked questions
What are the main GST rates in India?
Common slabs are 5%, 12%, 18%, and 28%. Some items are nil-rated or exempt. Always confirm the rate for your specific product or service with a tax professional.
What is the difference between inclusive and exclusive GST?
Exclusive means tax is added on top of the base price. Inclusive means the price you see already contains GST; the calculator backs out the base and tax portion.
Does this calculator file GST returns?
No. It only computes base, tax, and total from your inputs. Filing must be done through the GST portal or your accountant.