Percentage Calculator

Three small calculators that cover almost every percentage question: find a percentage of a number, compare two numbers as a percentage, and measure an increase or decrease. Each result can be copied or shared with a link.

Worked examples

What is 15% of 80? Multiply 80 by 0.15 to get 12. The same logic prices a tip, a discount, or a deposit.

30 is what percent of 120? Divide 30 by 120 and multiply by 100: 25%. Handy for test scores and progress against a target.

From 50 to 75 is what change? The difference of 25 divided by the starting value of 50 gives a 50% increase. Run it backwards, 75 to 50, and you get a 33.33% decrease, because the starting point changed. There is a dedicated percentage increase calculator for exactly these questions.

Frequently asked questions

How do I calculate one number as a percentage of another?

Divide the first number by the second and multiply by 100. Say you want 674 as a percentage of 12,518: 674 ÷ 12,518 × 100 gives about 5.38%. The second form above does this in one step.

How do I calculate a percentage increase?

Subtract the old value from the new one, divide by the old value, and multiply by 100. Going from 50 to 75: the difference is 25, divided by 50 gives 0.5, so that is a 50% increase.

Why is 50 to 75 a 50% increase but 75 to 50 only a 33% decrease?

Because each change is measured against its own starting point. The 25-point gap is half of 50 but only a third of 75. This asymmetry is normal and catches a lot of people out; a 50% drop needs a 100% gain to get back to where you started.

How do I find the original price before a discount?

Divide the discounted price by 1 minus the discount rate. If something costs 80 after a 20% discount, the original was 80 divided by 0.8, which is 100. Use the "X is Y% of what" form above for this.

What is the difference between percent and percentage points?

If an interest rate moves from 4% to 6%, it rose by 2 percentage points but by 50 percent (2 is half of 4). News headlines mix these up constantly. When comparing two percentages, points are usually the clearer measure.

Does this calculator store my numbers?

Calculations stay in your browser. The history panel uses your browser's session storage and empties itself when you close the tab. Nothing you type is sent to a server.

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