A percentage increase calculator answers a very specific question: by what percentage did a value grow from its starting point to where it ended up? That's a different question from a plain percentage calculation — it requires two numbers, a "before" and an "after," and a formula that measures the size of the change relative to where it started.
This page explains how to calculate percentage increase step by step, walks through several worked examples using real numbers, and covers how to calculate percentage change more broadly, since "increase" is one half of that broader concept. A working percent increase calculator is available above for anyone who wants the instant number without doing the arithmetic by hand. Browse all calculators if you need a different tool.
How to Calculate Percentage Increase: The Formula
The Percentage Increase Formula
The formula behind every percentage increase calculation is:
Percentage Increase = ((New Value − Old Value) ÷ Old Value) × 100
The "Old Value" is the starting point, the "New Value" is where the number ended up, and dividing the difference by the original value expresses the change relative to where it started — which is exactly why the same numeric change can represent very different percentage increases depending on the starting number. A $10 increase means far more as a percentage when the starting value is $20 than when it's $2,000.
This is the calculation people are describing when they search for how to calculate percentage increase, calculate increasing percentage, or determine increase in percentage — all three phrases point to this same formula.
Worked Examples: Percentage Increase in Practice
Example: Price Rising From $50 to $65
Old Value = 50, New Value = 65
(65 − 50) ÷ 50 = 0.30
0.30 × 100 = 30% increase
A price moving from $50 to $65 represents a 30% increase.
Example: Salary Increasing From $40,000 to $46,000
Old Value = 40,000, New Value = 46,000
(46,000 − 40,000) ÷ 40,000 = 0.15
0.15 × 100 = 15% increase
A salary rising from $40,000 to $46,000 is a 15% increase — a useful number to know when comparing a raise against inflation or a cost-of-living adjustment.
Example: Population Growing From 2,000 to 2,300
Old Value = 2,000, New Value = 2,300
(2,300 − 2,000) ÷ 2,000 = 0.15
0.15 × 100 = 15% increase
Even though the raw increase here (300) is much smaller than the salary example (6,000), the percentage increase comes out the same, because it's measured relative to a smaller starting value. This is exactly why percentage increase, not raw difference, is the number that makes different-sized comparisons meaningful.
How to Calculate Percentage Change (Increase vs. Decrease)
"Percentage change" is the broader term that covers both percentage increase and percentage decrease — the direction of the change determines which one applies. The formula is the same in both cases:
Percentage Change = ((New Value − Old Value) ÷ Old Value) × 100
If the result is positive, the value increased, and this percentage increase calculator is the right tool. If the result is negative, the value decreased, and the percentage decrease calculator is built specifically for that case, since decrease scenarios are often easier to reason about when the result is shown as a positive percentage removed rather than a negative percentage change.
Determining Increase in Percentage From Raw Numbers
When only the "before" and "after" numbers are available — no percentage given upfront — determining increase in percentage always starts the same way: subtract the old value from the new value to find the raw difference, divide that difference by the old value, then multiply by 100. This three-step process is the entire calculation, regardless of whether the numbers represent dollars, population counts, test scores, or any other measurable quantity.
Where a Percent Increase Calculator Is Used
Percentage increase calculations show up constantly across different contexts, each with slightly different stakes:
Business & Sales Growth
Comparing revenue, sales volume, or customer counts between two periods to express growth as a clean percentage figure, rather than a raw number that's hard to compare across different-sized businesses or time periods.
Salary & Budget Planning
Checking what percentage a raise, bonus, or budget increase actually represents, which matters more for planning purposes than the raw dollar figure alone.
Academic & Statistical Reporting
Expressing growth in survey results, population data, or experimental measurements as a percentage increase, which is the standard way these figures are reported in academic and professional writing.
Percentage Increase vs. Percentage Difference — Don't Confuse Them
Percentage increase and percentage difference are frequently mixed up, but they answer different questions. Percentage increase assumes direction — there's a clear "before" and "after," and the calculation measures growth relative to the starting point. Percentage difference, by contrast, is symmetrical — it compares two values without treating either one as the starting point, which produces a different formula and a different result even when applied to the same two numbers.
If the question involves a value changing over time or in a specific direction, this percentage increase calculator (or the percentage decrease calculator if the value went down) is the right tool. If the question is a neutral comparison between two independent figures, the percentage difference calculator is built for that instead.
Common Mistakes When You Calculate Increasing Percentage
Dividing by the new value instead of the old value. The percentage increase formula always divides by the original (old) value, not the final one — dividing by the wrong number produces a different, incorrect percentage.
Treating percentage increase and raw difference as the same thing. A $6,000 raise and a 300-person population increase can represent the same percentage increase (15%) despite being wildly different in absolute terms — the percentage only makes sense relative to its own starting value.
Applying the increase formula to a decrease. When the new value is smaller than the old value, the formula still works mathematically and returns a negative percentage, but it's usually clearer to use the dedicated percentage decrease calculator, which presents the result as a positive percentage decrease rather than a negative increase.
Frequently Asked Questions
How do I calculate percentage increase?
Subtract the old value from the new value, divide the result by the old value, then multiply by 100. For example, going from 50 to 65 is ((65 minus 50) divided by 50) times 100, which equals a 30% increase.
What's the formula for percentage increase?
Percentage Increase equals (New Value minus Old Value) divided by Old Value, multiplied by 100.
How do I calculate percentage change?
Percentage change uses the same formula as percentage increase. A positive result means the value increased, and a negative result means it decreased.
What is the percentage increase from 40,000 to 46,000?
That is a 15% increase, calculated as ((46,000 minus 40,000) divided by 40,000) times 100.
How do I determine increase in percentage when I only have the before and after numbers?
Subtract the before value from the after value to get the raw difference, divide that difference by the before value, then multiply by 100.
Is percentage increase the same as percentage difference?
No. Percentage increase measures directional change from a starting value to an ending value. Percentage difference is a symmetrical comparison between two values with no assumed direction, and typically produces a different result.
Can this calculator handle percentage increases over 100%?
Yes. If a value more than doubles, the calculator correctly returns a percentage increase above 100%.
Is this percent increase calculator free to use?
Yes. It is free, requires no sign-up, and returns results instantly as values are entered.