Percentage Increase Calculator

Percentage Increase Explained

Percentage increase measures how much a value has grown relative to where it started. It's one of the most widely used calculations in everyday finance and business, showing up in salary raises, price hikes, sales growth, population changes, and investment returns. Unlike a simple difference between two numbers, percentage increase expresses that change relative to the starting point, which is what makes it useful for comparison. A $10 raise means very different things depending on whether your salary was $100 or $10,000, and percentage increase is what captures that difference properly.

The Percentage Increase Formula

To find how much a number has increased in percentage terms, subtract the original value from the new value, divide that difference by the original value, then multiply by 100.

Example: A product priced at $80 is now selling for $100. The increase: ((100 − 80) ÷ 80) × 100 = 25%. The price went up by 25%.

If the result comes out negative, that means the value actually went down, not up, and you're looking at a percentage decrease rather than an increase.

Finding the New Value After a Percentage Increase

Sometimes you already know the original number and the percentage it's going to increase by, and you need to find what the new value will be. This comes up when calculating raises, markups, or projected growth.

Example: Your salary of $250 per week gets a 12% raise. New value: 250 × (1 + 12 ÷ 100) = 250 × 1.12 = $280 per week.

This same formula works for compound scenarios too, like calculating a price after multiple sequential increases, though each increase needs to be applied one at a time since they compound rather than simply add together.

Working Backward: Finding the Original Value

This is the calculation people get wrong most often. If you know the final value after an increase and the percentage it increased by, you can't just subtract that percentage from the new value to get the original, because the percentage was applied to the original number, not the new one.

Example: A jacket now costs $336 after a 12% price increase. To find the original price: 336 ÷ (1 + 12 ÷ 100) = 336 ÷ 1.12 = $300. The jacket originally cost $300, not $336 minus 12% of $336.

This distinction matters a lot in retail and finance. If you take 12% off $336 directly, you get $295.68, which is the wrong answer. The correct method divides by 1.12 rather than subtracting 12% from the final figure, because the 12% increase was calculated against the smaller, original number.

Where Percentage Increase Calculations Matter Most

In business, percentage increase tracks revenue growth quarter over quarter, helps set pricing strategy, and measures how marketing campaigns perform against previous periods. In personal finance, it's used to understand salary growth, inflation's effect on purchasing power, and investment returns over time. In real estate, property value increases are almost always discussed in percentage terms rather than raw dollar amounts, since percentage figures make it easier to compare markets of different price ranges. Retailers use the reverse calculation constantly too, working backward from a marked-up price to verify the original wholesale cost.

A Common Point of Confusion

People sometimes assume that increasing a number by X% and then decreasing it by X% returns you to the original value. It doesn't. Because percentage increase and decrease are each calculated against a different base number, the two operations aren't symmetric. A value that goes up 25% and then down 25% ends up lower than where it started, since the 25% decrease is calculated on the larger, already-increased number. Keeping track of which number a percentage is being applied to is the key to avoiding mistakes in any percentage increase calculation.