Free Online Percentage Calculator for Everyday and Business Use

PercentNinja is an independent UK-based tool site created to help businesses, online sellers, and individuals perform accurate percentage and pricing calculations quickly.

PercentNinja is a free online percentage calculator designed to help you solve everyday percentage problems quickly and accurately. Whether you need to work out a discount, calculate VAT, measure a percentage increase, or compare two values, our tools provide instant results with clear explanations.

Built for real-world use, PercentNinja is helpful for shopping, budgeting, business pricing, and education. Shoppers can calculate sale prices and savings, students can check percentage calculations, and businesses can work out margins, markups, and pricing adjustments without complex formulas or spreadsheets.

PercentNinja is especially useful for users in the UK, with dedicated VAT calculators and pricing tools designed for common UK scenarios. You can add VAT, remove VAT from a total, or calculate the original price before tax quickly and accurately. All calculators work with any currency or value.

Each calculator includes simple formulas, worked examples, and frequently asked questions so you can understand how the result is calculated. This makes PercentNinja more than just a quick answer tool — it’s a practical resource for learning and applying percentage calculations with confidence.

Use the tools below to calculate percentages instantly, analyse changes over time, and make better pricing or budgeting decisions. PercentNinja brings together a complete set of free percentage calculators in one place to save time and avoid manual calculations.