how do i calculate percentage increase

What Is Percentage Increase?

Percentage increase tells you how much a value has gone up, relative to where it started. Instead of just saying “it increased by 20,” percentage increase says “it increased by 25%,” which gives better context.

For example, if your monthly utility bill rises from $120 to $150, the increase is $30. But how big is that increase compared with your original $120? That is what percentage increase measures.

The Formula for Percentage Increase

You can think of it in three simple steps:

• Find the difference: New - Original
• Divide by the original value
• Multiply by 100 to convert to a percent

Step-by-Step Example

Example: Price increases from 80 to 100

• Difference = 100 - 80 = 20
• 20 ÷ 80 = 0.25
• 0.25 × 100 = 25%

So the percentage increase is 25%.

Quick Mental Shortcut

If you already know the increase amount, divide that increase by the original value:

This is the same formula, just rewritten in a faster form.

Common Mistakes to Avoid

1) Dividing by the new value instead of the original value

Always divide by the original amount when calculating percentage increase.

2) Forgetting to multiply by 100

If your result is 0.18, that means 18%, not 0.18%.

3) Mixing up increase and decrease

If the new value is lower than the original, that is a percentage decrease, not increase. The calculator above will show this clearly.

Real-Life Uses

• Personal finance: salary raises, rent changes, grocery inflation
• Business: revenue growth, customer growth, ad spend changes
• Investing: stock price movement, portfolio gains
• School and research: test score improvements, trend comparisons

Percentage Increase vs Percentage Points

These are not the same thing:

• Percentage points are a direct subtraction of percentages (e.g., 10% to 14% = +4 percentage points).
• Percentage increase compares relative growth (from 10% to 14% is a 40% increase).

Knowing the difference helps avoid major interpretation errors in finance and statistics.

How to Calculate Percentage Increase in Excel or Google Sheets

If original value is in cell A2 and new value is in B2, use:

Then format the cell as a percentage. If you want it directly in percent number form:

Special Cases

If the original value is 0

Percentage increase from zero is not defined in the usual way because division by zero is impossible. The calculator will show a message for this case.

If values are negative

Percentage change with negative starting values can be tricky to interpret. In many practical contexts (prices, counts, sales), values are non-negative, which makes interpretation straightforward.

FAQ

How do I find percent increase quickly?

Subtract old from new, divide by old, multiply by 100.

Can percentage increase be over 100%?

Yes. If the new value is more than double the original value, the increase is greater than 100%.

What if the result is negative?

A negative result means the value decreased.

Bottom Line

If you remember one formula, remember this:

Use the calculator at the top anytime you need a fast, accurate answer. Whether you are checking a raise, comparing prices, or measuring growth, this method gives you a clear and consistent percentage increase.