How to use the percentage calculator
- Pick the calculator that matches your question. All four are on the page at once, so there's nothing to switch.
- Enter the two numbers. You can type decimals and commas, such as 1,250.50.
- For "increase or decrease", choose the direction with the Increase and Decrease buttons.
- Read the answer under each calculator. It appears as a full sentence, such as "15% of 2,400 is 360", so it's easy to copy into a message or report.
Features
- What is X% of Y – discounts, tips, commission and marks.
- X is what percent of Y – exam scores, survey results and shares of a budget.
- Percentage change from X to Y – price rises, salary changes and growth, clearly labelled as an increase or a decrease.
- Increase or decrease a value by a percentage – add a mark-up or take off a discount in one step.
- Answers update as you type, with no button to press.
- Clear messages when a field is empty, contains something that isn't a number, or would mean dividing by zero.
The formulas, with worked examples
Percentage of a number: result = percentage ÷ 100 × value. A 15% discount on a 2,400 bill is 360.
What percent one value is of another: result = part ÷ total × 100. 45 marks out of 60 is 75%.
Percentage change: result = (new − old) ÷ old × 100. Rent rising from 80,000 to 100,000 is a 25% increase. Going the other way, from 100,000 to 80,000, is a 20% decrease. The same gap gives a different percentage because the starting point is different.
Increase or decrease by a percentage: result = value × (1 ± percentage ÷ 100). Increasing 1,200 by 15% gives 1,380. Decreasing 500 by 20% gives 400.
Percentage change or percentage points?
News reports and bank letters often mix these up. When a rate moves from 10% to 12%, the difference is 2 percentage points. As a percentage change, though, the rate has gone up by 20%, because 2 is a fifth of 10. Use the percentage change calculator when you want the relative change, and simply subtract the two percentages when you want the gap in points.
Everyday uses
- Shopping: a 30% sale on a 4,500 jacket takes off 1,350, so you pay 3,150. Use "increase or decrease" with Decrease to get the final price in one step.
- Exam results: 412 marks out of 550 is about 74.91%. Enter 412 as the value and 550 as the total.
- Salary and prices: a pay rise from 85,000 to 95,000 is an increase of about 11.76%, which you can compare with inflation over the same period.
- Business: adding a 20% mark-up to a cost of 750 gives a selling price of 900. Note that 150 of profit is 20% of the cost but only about 16.67% of the selling price, so be clear which one people mean by margin.
- Tips and service charges: 10% of a 3,640 restaurant bill is 364.
Why use Fileora's percentage calculator
Most percentage questions are one of four types, and it's easy to divide by the wrong number when you work them out by hand. Having all four calculators side by side means you can pick the one that fits, and the full-sentence answer confirms you asked the right question.
The calculator is free, needs no sign-up and works on any phone or computer. Your numbers stay on your device because nothing is sent to a server.
If you're working with tax, try the GST calculator, which adds or removes GST and sales tax for you. For loans, the EMI calculator turns an annual interest rate into a monthly instalment and a full repayment schedule.