TOOLS2030 / Calculators

Percentage, Discount, GST and VAT Calculations Explained

Percentages are used in discounts, taxes, markups, tips and business calculations. Understanding the base amount is the key to getting the right answer.

Basic percentage

To find 20% of 500, multiply 500 by 0.20. The result is 100. The Percentage Calculator is useful when you need the percentage of a number, a percentage change or the value represented by a percentage.

Discount calculation

A 25% discount on 1,000 means a saving of 250 and a final price of 750. Use the Discount Calculator to see both the saving and sale price.

Adding GST or VAT

If a price before tax is 1,000 and the tax rate is 15%, the tax amount is 150 and the total is 1,150. Removing tax from a tax-inclusive amount is different because the percentage is calculated from the pre-tax value. The GST/VAT Calculator can handle add/remove workflows.

Markup and profit margin are not the same

Markup is normally measured against cost, while profit margin is measured against selling price. Confusing the two can produce incorrect pricing. Use the Price Markup Calculator and Profit Margin Calculator for the appropriate method.

Check the base amount

Most percentage mistakes happen because the wrong number is used as the base. Before calculating, identify whether the percentage applies to cost price, selling price, bill subtotal, pre-tax price or another amount.