Percentage Calculator - 4 Calculators in One

How the Percentage Calculator Works

1. 01Choose the type of calculation: percentage of a number, percentage change, or what percentage one number is of another
2. 02Enter your values in the input fields
3. 03The result is calculated instantly as you type
4. 04Use the clear button to start a new calculation

Common Percentage Calculations Explained

Percentage calculations come up frequently in everyday life: discounts while shopping, tax calculations, grade scoring, and tip calculations. To find X% of a number, multiply the number by X/100. To find the percentage change between two values, divide the difference by the original value and multiply by 100. A percentage increase from 50 to 75 is 50%, not 25%.

When to Use a Percentage Calculator

Use this calculator whenever you need quick, error-free percentage math. Common scenarios include calculating sale discounts while shopping (e.g., 30% off a $89 item), determining tax amounts on invoices, computing grade percentages for school or university, figuring out tip amounts at restaurants, and analyzing percentage changes in business metrics like revenue growth or stock price movements.

Common Use Cases

• —Calculate sale discounts while shopping (e.g., 30% off a $89 item)
• —Determine tax amounts on invoices and purchases
• —Compute grade percentages for school assignments and exams
• —Calculate tip amounts at restaurants using the built-in tip calculator
• —Analyze percentage changes in business metrics like revenue growth or stock prices

Expert Tips

• ✻For percentage change, always divide by the original value - dividing by the new value is a common error that gives wrong results
• ✻To reverse a discount (find the original price), divide the discounted price by (1 - discount rate as decimal)
• ✻Remember that percentage points and percentages are different: going from 3% to 5% is a 2 percentage point increase but a 66.7% relative increase

Frequently Asked Questions

How do I calculate a percentage of a number?→

Multiply the number by the percentage and divide by 100. For example, 25% of 200 is (25 / 100) x 200 = 50. This calculator does the math instantly as you type.

What is the formula for percentage change?→

Percentage change = ((new value - old value) / old value) x 100. For example, if a price goes from $80 to $100, the percentage change is ((100 - 80) / 80) x 100 = 25% increase.

What is the difference between percentage points and percent?→

A percentage point is an absolute difference between two percentages. If interest rates rise from 3% to 5%, that is a 2 percentage point increase, but a 66.7% relative increase. This distinction matters in finance, politics, and statistics.

Is this percentage calculator free to use?→

Yes, completely free. The calculator runs entirely in your browser - no data is sent to any server, and there are no ads.

Can I use this for calculating discounts and sales tax?→

Yes. To find a discount, use the 'X% of Y' calculator - for example, 20% of $150 gives you $30 (the discount amount). For sales tax, enter the tax rate and pre-tax price to get the tax amount. The tip calculator section also handles restaurant tips.