Percentage Increase Calculator: A Complete Guide (With Examples)

What Is Percentage Increase?

A percentage increase tells you by what proportion a value has grown relative to its original value. In other words:

“How much bigger is the new value compared to the original, expressed as a percentage of the original?”

If your original (starting) value is

A

, and the new (final) value is

B

, then:

• If

  B > A

  , we have an increase.
• If

  B = A

  , the percentage increase is 0%.
• If

  B < A

  , technically it’s a percentage decrease (we’ll note that nuance later).

The Formula for Percentage Increase

The standard formula is:

Percentage Increase = ((B - A) / A) × 100

Or, written in steps:

1. Subtract the original value

   A

   from the new value

   B

   .
2. Divide that increase by the original value

   A

   .
3. Multiply by 100 to convert to a percentage.

If the result is negative, it means

B < A

, and you're looking at a decrease.

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Step‑by‑Step Guide with Examples

Let’s walk through examples to make everything crystal clear.

Example 1: Simple Increase

Your old monthly rent was $800. Now rent is $1,000. What is the percentage increase?

Increase = 1000 - 800 = 200  
Percentage Increase = (200 / 800) × 100 = 25%

So, the rent increased by 25%.

Example 2: Over 100% Increase

A stock was $50, and now it's $125. What is the percentage increase?

Increase = 125 - 50 = 75  
Percentage Increase = (75 / 50) × 100 = 150%

The stock increased by 150% — it more than doubled.

Example 3: Negative Change (Decrease)

If a price moves from $120 down to $90:

Increase = 90 - 120 = -30  
Percentage Change = (-30 / 120) × 100 = -25%

That negative sign indicates a 25% decrease.

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Percentage Increase vs Percentage Point Difference

A common source of confusion is between percentage increase and percentage point change.

• Percentage increase is relative (how much in percent the value has grown).
• Percentage point is the absolute difference between two percentages.

For example: If a metric goes from 20% to 22%, the percentage increase is:

(22 - 20) / 20 × 100 = 10%

But the change in percentage points is simply

22% - 20% = 2

percentage points.

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Handling Multiple Sequential Changes

Sometimes a value changes multiple times in sequence — e.g. +10% then +20%. You cannot just add percentages (i.e. you can’t say 10% + 20% = 30%). Instead, apply them stepwise:

Step 1: New Value After First Change = A × 1.10  
Step 2: New Value After Second Change = A × 1.10 × 1.20

The net effect is multiplicative, not additive.

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Common Mistakes to Avoid

1. Using the wrong base (original) value — your denominator must be the starting value.
2. Confusing with percentage point change (see prior section).
3. Dividing by zero — original value

   A

   cannot be zero.
4. Rounding too early — keep precision until final step.
5. Ignoring sign / negative results — interpret negative as decrease.

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Why Use an Online Percentage Increase Calculator?

Using a web-based percentage increase calculator helps by:

• Avoiding human error in arithmetic.
• Handling decimals or large numbers reliably.
• Producing results instantly (mobile & desktop).
• Supporting more complex cases like chained increases or formatting.

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How to Use Our Percentage Increase Calculator

Here's how to use the calculator on your site (or similar):

1. Enter the Original Value.
2. Enter the New Value.
3. Click “Calculate”.
4. View the Percentage Increase result.
5. If the result is negative, it indicates a percentage decrease (see our percentage decrease calculator).

You can also explore related tools like what percent is A of B or percent of a number.

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Real‑World Use Cases

• Finance / Investing: Measuring return on investment (ROI).
• Retail / Pricing: Evaluating price hike percentages.
• Salaries / Raises: Expressing raises as percentages.
• Data Analysis: Comparing growth metrics across periods.
• Population Growth / Inflation: Reporting percent changes over time.

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Conclusion & Call to Action

Understanding percentage increase is essential across finance, business, science, and everyday life. With the formula:

(B - A) / A × 100

you can compute it confidently. Use our free Percentage Increase Calculator to validate your numbers instantly — no manual math mistakes.

Try it now, and don’t forget to explore:

• Percentage Decrease
• Percent of a Number
• What Percent is A of B

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FAQ

Q: Can the original value A be zero?
A: No — dividing by zero is undefined. If A = 0, you can’t compute a percentage increase.

Q: What if the result is negative?
A: A negative result implies a percentage decrease.

Q: How many decimal places should I show?
A: For general use, 1 or 2 decimals are often enough (e.g. 12.34%). For scientific or financial data, use more precision.

Q: Does 100% increase mean doubling?
A: Yes. If something increases by 100%, the final value is twice the original.

Example Calculation

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Try It Yourself

If you want to explore more tools like this, check out our full collection of online percentage calculators for everything from discounts to tax and profit margin formulas.