Invoice Total Calculator

When this applies

• You are building an invoice and want the line total to be right.
• You are checking a supplier's invoice arithmetic.
• You are quoting a customer and want the tax and total shown separately.
• You want to see the taxable value after a discount.

1 unit at INR 10,000 with 18% tax

1. 1Quantity 1, rate INR 10,000, no discount.
2. 2Taxable value = 1 x 10,000 = INR 10,000.
3. 3Tax = 10,000 x 18 / 100 = INR 1,800.
4. 4Invoice total = 10,000 + 1,800 = INR 11,800.

Taxable value INR 10,000, tax INR 1,800 and total INR 11,800.

What this calculator does

Total a line item with quantity, rate, discount, tax and other charges, showing the taxable value, the tax and the invoice total as separate figures.

How this is calculated

The taxable value is the quantity multiplied by the rate, less any discount. Tax is charged on that taxable value at the rate you set, and other charges such as freight are added. The invoice total is the taxable value plus tax plus other charges. Applying the tax after the discount is what keeps the tax on the value actually charged.

The formula

Taxable = qty × rate − discount · Total = taxable + tax + other

Common mistakes to avoid

• Charging tax before the discount

  Tax on the pre-discount value charges tax on money the customer never paid. Apply the discount first.

• Leaving freight out of the taxable value

  Where freight is part of your supply it generally belongs in the taxable value, so tax applies to it too.

• Assuming the total makes a valid invoice

  A compliant tax invoice needs the prescribed particulars. The arithmetic alone is not enough.

Frequently asked

Is tax charged before or after the discount?

A discount shown on the invoice and agreed at or before the supply reduces the taxable value, so the tax is charged after it. This calculator applies the tax to the post-discount value.

What is the taxable value?

Quantity times rate, less discount. It is the value on which GST is charged and is shown separately on a tax invoice.

Are other charges taxed?

Charges that form part of the supply, such as freight where you are the supplier, are generally included in the value on which tax is charged. The treatment can depend on the contract, so check before invoicing.

Does this produce a GST-compliant invoice?

No. It computes the totals. A valid tax invoice also needs the prescribed particulars - GSTIN, HSN or SAC, place of supply and the tax split - which this calculator does not produce.

Can I use it for a multi-line invoice?

Yes, one line at a time, then add the line totals. Each line can carry its own rate.