Free Finance Calculators
Work out sale prices, discounts, VAT and GST in seconds. Each finance calculator shows the arithmetic clearly, runs in your browser, and needs no signup.
Last updated: November 2026
Prices, Discounts and Sales Taxes
These calculators cover the everyday price maths behind shopping, invoicing and quoting: how much a discount saves you, what a price is with tax added, and what a tax-inclusive price was before tax.
Discount Calculator
Find the sale price and the amount you save from a percentage or fixed discount.
VAT Calculator
Add VAT to a net price or remove it from a gross price, with rate presets sourced from official tax authority pages.
GST Calculator
Add GST to a price or remove it from a GST-inclusive total, with presets for Australia, New Zealand, Singapore, Canada and India.
Which Finance Calculator Should I Use?
| If you want to… | Use |
|---|---|
| See the price after a percentage or fixed amount off | Discount Calculator |
| Add VAT to a price, or split a VAT-inclusive price into net and VAT | VAT Calculator |
| Add GST to a price, or split a GST-inclusive price into net and GST | GST Calculator |
| Work out a percentage of a number, or a percentage change | Percentage Calculator |
How These Calculators Work
Adding and removing a percentage
Adding a tax or removing a discount is a percentage calculation. To add a rate r percent, multiply the price by (1 + r/100). To take a percentage off, multiply by (1 − r/100). Removing a tax that is already included works the other way round: divide the tax-inclusive price by (1 + r/100), because the tax was calculated on the pre-tax price, not on the total.
Why the order of steps matters
A discount followed by tax gives a different total from tax followed by a discount, because each percentage applies to a different base. When you compare prices, check whether a quoted price already includes tax and whether a discount was applied before or after it.
Rounding
Money is usually rounded to the nearest cent or penny. Results here are shown to two decimal places, so a total built from several rounded lines can differ by a cent from one rounded at the end.
Frequently Asked Questions
What finance calculators are available?
There are three finance calculators: the Discount Calculator for sale prices and savings, the VAT Calculator for adding or removing value-added tax, and the GST Calculator for adding or removing goods and services tax.
Are these finance calculators free?
Yes. Every calculator is free to use as often as you like, with no signup and no download.
Is my financial data stored or sent anywhere?
No. All calculations run in your browser. The prices and rates you type are not sent to a server, stored or shared.
Can I use these calculators as tax or financial advice?
No. The results are arithmetic estimates for planning and comparison. Tax rules and rates change and differ by country, region and product, so confirm the rate that applies to you with your tax authority or a qualified adviser before filing or invoicing.
What is the difference between VAT and GST?
Both are consumption taxes added to the price of goods and services. The name differs by country: VAT is the term used in the UK and the European Union, while GST is the term used in countries such as Australia, New Zealand, Canada, India and Singapore. The arithmetic for adding or removing the tax is the same.
How do I take a percentage off a price?
Multiply the price by the discount percentage divided by 100 to get the saving, then subtract the saving from the price. For example, 20% off 80 is a saving of 16, so the sale price is 64. The Discount Calculator does this for you.
Last reviewed: November 2026 — formulas and worked examples verified.