Percentage Increase Calculator

How to Calculate Percentage Increase

Percentage increase measures how much a value has grown relative to its starting point. It's used everywhere — from tracking salary raises and stock returns to monitoring website traffic growth and population changes. Understanding this calculation helps you make sense of change over time.

The Formula: ((New Value − Original Value) ÷ Original Value) × 100

The key insight is that you divide by the original value, not the new one. This anchors the change to where you started. A jump from 80 to 100 is a 25% increase, but a jump from 100 to 120 is only a 20% increase — even though both are a difference of 20.

Practical Examples

• Salary: Your annual salary went from $52,000 to $58,000. That's an 11.54% raise — well above the typical 3–4% cost-of-living adjustment.
• Rent: Monthly rent increased from $1,200 to $1,380. Enter these values above to find it's a 15% hike.
• Investment: A stock price rose from $45 to $63. That's a 40% gain. Learn how growth compounds over time in our guide on compound interest.
• Website traffic: Monthly visitors grew from 8,000 to 12,400 — a 55% increase worth celebrating.

Increase vs. Decrease

If the new value is actually lower than the original, the result will be negative — indicating a decrease, not an increase. For a dedicated tool, use our Percentage Decrease Calculator. You can also compare two values symmetrically with the Percentage Difference Calculator.

For a step-by-step walkthrough with more examples, read our article on how to calculate percentage increase.

Common Percentage Increase Examples

Use the quick-answer table below — every row links to the calculator with the values pre-filled so you can verify or tweak in one click.

Looking for a different base value? Just enter your own numbers in the calculator above — the same formula applies to any pair of values.

The Formula Explained in Plain English

Every percentage increase answers one question: how big is the growth compared with where we started? Break it into three moves and it stops being intimidating:

1. Measure the growth. New − Original. From 80 to 100, the growth is 20.
2. Compare it with the starting point. 20 ÷ 80 = 0.25. The growth is a quarter of where you began.
3. Turn the ratio into a percentage. 0.25 × 100 = 25%.

A useful shortcut for the reverse direction: to apply an increase, multiply by (1 + rate). A 12% increase on 450 is 450 × 1.12 = 504. To undo one, divide instead of subtracting — that is what the Reverse Percentage Calculator does.

Visualising a Percentage Increase

Seeing the size of the change next to the original value makes the number intuitive. Each bar below shows how much is added on top of a base of 100:

Light bar = the original value. Solid bar = the increase added on top.

Common Mistakes to Avoid

• Dividing by the new value. The denominator is always the original. Using 100 instead of 80 in the example above gives 20% — a wrong answer that looks plausible.
• Adding percentages that stack. Two consecutive 10% increases are not 20%. 100 → 110 → 121, which is a 21% total increase.
• Confusing percent with percentage points. A rate moving from 4% to 6% is a rise of 2 percentage points, but a 50% increase.
• Assuming increase and decrease cancel out. +50% then −50% leaves you at 75% of where you started, not back to even.
• Starting from zero. Percentage increase is undefined when the original value is 0 — there is nothing to compare the growth with. Report the absolute change instead.
• Rounding too early. Round only the final answer; rounding the intermediate ratio can shift the result by a full percentage point.

Where People Use Percentage Increase

How This Calculator Works

The calculation runs entirely in your browser using standard double-precision arithmetic: the difference is divided by the absolute value of the original figure and multiplied by 100, then displayed to two decimal places. Nothing is sent to a server and no values are stored. If the original value is 0, the tool reports "N/A" rather than an infinite result.

Method reference: the percentage-change definition used here follows standard arithmetic conventions described in relative change and difference and the percentage-point distinction used by statistical agencies such as the U.S. Bureau of Labor Statistics when reporting price change. Reviewed and maintained by the Snap Percent Calc editorial team.