TechnWaves GST Calculator

Calculate GST online for inclusive or exclusive prices. Check taxable value, GST amount and final total instantly.

Use this GST calculator to add GST to a base amount or remove GST from an inclusive price. It shows taxable value, GST amount and final total clearly.

It is helpful while preparing invoices, checking supplier bills, comparing product prices or confirming whether a quote includes tax.

Inclusive and exclusive GST are easy to mix up. If a customer approved Rs. 10,000 including GST, do not add GST again. Reverse-calculate the taxable value first, then show the GST portion correctly in your invoice or quote.

The calculator is only for arithmetic. It does not decide whether CGST/SGST or IGST applies, which HSN/SAC code to use, or whether your business should charge GST. Confirm the GST rate and tax treatment before using the result in a final document.

When should you use this tool?

• You know the base price and need the GST-inclusive total.
• You have a final price and need to find the GST portion inside it.
• You want to compare 5%, 12%, 18% or 28% GST slabs.
• You need quick numbers before preparing an invoice or quotation.

How to use this tool

• Enter the amount you want to calculate.
• Choose whether GST should be added or removed.
• Select the GST rate that applies to your product or service.
• Review the taxable amount, GST amount and total amount.
• Use the result only after confirming the correct GST rate and tax treatment.

Example: ₹10,000 product with 18% GST

If a product has a taxable value of ₹10,000 and GST is 18%, the GST amount is ₹1,800 and the final amount is ₹11,800.

If ₹11,800 is already inclusive of 18% GST, the calculator can reverse the amount and show ₹10,000 taxable value and ₹1,800 GST portion.

Before using those numbers in an invoice, the seller should still check whether 18% is the correct rate and whether the customer is in the same state or another state. The calculator helps with numbers, not tax classification.

Common mistakes to avoid

• Adding GST again to an already inclusive price.
• Selecting the wrong GST slab.
• Confusing CGST/SGST and IGST treatment.
• Using rounded values without checking final paise or rupees.
• Using the calculator result without verifying the product classification.
• Forgetting to update invoice totals after changing quantity or discount.

Tax accuracy note

This calculator helps with arithmetic. It does not decide GST registration, HSN/SAC classification, place of supply or return filing rules. Check tax-sensitive cases with an accountant.

Frequently Asked Questions

How do I add GST to an amount?

Multiply the taxable amount by the GST rate and add the tax to the base amount. For ₹10,000 at 18%, GST is ₹1,800 and total is ₹11,800.

How do I remove GST from inclusive price?

Use the remove GST option. The calculator divides the final price by one plus the GST rate to find taxable value.

Which GST rates are available?

The tool includes common slabs such as 5%, 12%, 18% and 28%. Your actual product or service may need confirmation.

Can I use this for invoices?

Yes, use it to check numbers before entering them in the invoice generator. Verify rate and tax breakup before sending.

Does this calculate CGST and SGST separately?

The calculator shows total GST. If needed, split 18% into 9% CGST and 9% SGST for many same-state transactions.

When is IGST used?

IGST is commonly used for inter-state supplies. The exact treatment depends on place of supply and business details.

Why are inclusive and exclusive GST different?

Exclusive GST adds tax on top of base value. Inclusive GST means the final price already contains tax, so the base value must be reverse-calculated.

Is this tax advice?

No. It is a simple calculator. For registration, filing and classification decisions, speak with a qualified professional.

Related Guides

• How to Add GST to Your Invoice
• GSTIN on Invoice

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• Quotation Generator
• Profit Margin Calculator