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IHaveTool

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Sales Tax Calculator

Add tax to a price or remove tax from a tax-inclusive price at any rate — for sales tax, VAT, or GST. Includes per-unit and order totals. Runs in your browser.

Switch between adding tax to a net price and extracting tax from a tax-inclusive price. You supply the rate, so it works anywhere — nothing is looked up and nothing is sent to a server.

Amount & rate

Price before tax

Display only — no conversion

Total including tax

$108.50

Per unit: $100.00 net + $8.50 tax at 8.5% = $108.50.

Per unit

Net (excl. tax)
$100.00
Tax
$8.50
Gross (incl. tax)
$108.50

Totals

Total net
$100.00
Total tax
$8.50
Total gross
$108.50
How is this calculated?

Add tax: Tax = Net × rate ÷ 100; Gross = Net + Tax

Remove tax: Net = Gross ÷ (1 + rate ÷ 100); Tax = Gross − Net

Totals = per-unit value × Quantity

Adding vs. removing tax

Adding tax starts from a price that excludes tax and works out the tax and the final total. Removing tax starts from a price that already includes tax and works backward to the net amount — useful for invoices and bookkeeping.

Sales tax, VAT, and GST

These are different consumption-tax systems, but each applies a percentage to a price. Because you enter the rate, the same calculator handles all of them — the only thing that changes is the number you type in.

Getting the rate right

The result is only as accurate as the rate you enter. Rates differ by location and product type and can change, so confirm the current official rate for your situation before relying on the figures.

Frequently asked questions

What is a sales tax calculator?

It adds tax to a price, or removes tax from a tax-inclusive price, at a rate you provide. It works for any percentage-based tax — sales tax, VAT, or GST — and shows the net, tax, and gross amounts.

How do I add sales tax to a price?

Multiply the price by the tax rate divided by 100 to get the tax, then add it to the price. For example, $100 at 20% is $20 tax and a $120 total. Use the “Add tax” mode above.

How do I remove tax from a tax-inclusive price?

Divide the gross price by (1 + rate ÷ 100) to get the net amount, then subtract it from the gross to find the tax. For example, $120 at 20% has a $100 net and $20 tax. Use the “Remove tax” mode.

What is the difference between sales tax, VAT, and GST?

They are different names and systems for consumption tax used in different countries, but the arithmetic of adding or extracting a percentage is the same. This calculator handles all of them because you enter the rate yourself.

What tax rate should I use?

Use the rate that applies to your product and location. Rates vary by country, state, and category and change over time, so check the current official rate for your situation — this tool does not look rates up for you.

Can I calculate tax for multiple items?

Yes. Enter a quantity and the calculator multiplies the per-unit net, tax, and gross to give totals for the whole order.

Is this tax advice?

No. It is a math tool for a rate you supply. For questions about which rate applies, registration, or filing, consult the relevant tax authority or a qualified professional.

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