Math Tools

Percentage Increase Calculator

Find what percentage your value increased or decreased.

Original Value

New Value

Percentage Change

+50.00%

increase

Absolute Change50

Original100

New150

What is the Percentage Increase Calculator?

A percentage increase is the proportional growth from an original value to a new value, expressed as a percentage. It tells you how much something has grown relative to where it started, making it easy to compare changes across different scales. For example, a salary jump from £40,000 to £50,000 is a 25% increase, while the same £10,000 added to £200,000 is only a 5% increase—the percentage reveals the true impact.

How it works

The calculator subtracts the original value from the new value to find the absolute increase, then divides that by the original value and multiplies by 100 to get the percentage. This normalises the growth relative to the starting point, so you can fairly compare increases across different base amounts. A larger original value typically results in a smaller percentage, even if the absolute pounds or dollars gained are the same.

Percentage Increase = ((New Value − Original Value) / Original Value) × 100

New Value is what you have now; Original Value is what you started with. The result is always shown as a percentage (%). A positive result means growth; a negative result (if New Value < Original Value) indicates a decrease instead.

Examples

Input	Result	Notes
Original: 80, New: 100	25%	The value grew by 20 units; 20÷80 = 0.25 = 25% increase
Original: £50,000, New: £62,500	25%	A £12,500 raise; commonly quoted when salaries jump a quarter
Original: 1200, New: 1500	25%	Even with a different scale, the percentage is the same because 300÷1200 = 25%

Benefits

Compare growth fairly—a 20% increase is meaningful whether you started at £100 or £10,000

Assess salary or wage negotiations quickly without a calculator

Track investment performance and portfolio growth over time

Evaluate business metrics like revenue, user sign-ups, or market share increases

Communicate change clearly; percentage is more intuitive than raw numbers

Spot inflation impact on costs or spot check your bank interest rates

Tips & common mistakes

Common mistakes

Reversing the values—always use (New − Original) ÷ Original, never Original ÷ New

Forgetting to multiply by 100—the formula gives a decimal, so 0.25 must become 25%

Confusing percentage increase with percentage of total; a 50% increase on £100 is £150, not 50% of 100

Tips

If the result is negative, you have a percentage decrease, not an increase—check whether that's what you expected

Always verify your original value is correct; a small error there can skew the percentage significantly

For rough mental math, remember 10% is always one-tenth of the original—useful to sanity-check your calculator output

Frequently asked questions

What if the new value is less than the original?

The calculator will show a negative percentage, which is a decrease. For example, going from 100 to 75 is −25%, a drop of one quarter.

Is percentage increase the same as percentage profit?

In profit, you also subtract costs; percentage increase is purely the ratio of growth to the starting value, so they differ if there are expenses involved.

Can I use this for fractional or decimal values?

Yes. The calculator works with any number—£99.99 to £124.99 will give you a 25% increase, even with pence included.

Why does a 50% increase then a 50% decrease not return to the original?

Because percentages are applied to different bases. A 50% increase on 100 gives 150; a 50% decrease on 150 gives 75. The percentage is calculated from the new base each time.

How do I calculate percentage increase over multiple years?

For a simple total, use the first year value as original and the last year as new. For yearly compound growth, you'd need to apply the percentage to each year individually or use a compound growth formula instead.

Is this the same as calculating a raise or bonus?

Yes, a salary raise is a percentage increase. If you're offered a 10% raise, multiply your current salary by 0.10 and add it to find your new salary.