calculating percentage increase

What is percentage increase?

Percentage increase tells you how much a value has grown compared to where it started. Instead of just saying “it went up by 20,” percentage increase puts that change into context by comparing it to the original value. This is useful for prices, salaries, savings, traffic, sales, production, and almost any type of trend data.

For example, if a product price moves from $20 to $25, the increase is $5. But percentage increase tells us that $5 is 25% of $20, so the price increased by 25%.

The formula for calculating percentage increase

Use this formula:

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

You can think of it as three simple operations:

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

Step-by-step example

Example: From 80 to 100

• Original value = 80
• New value = 100
• Change = 100 - 80 = 20
• Relative change = 20 / 80 = 0.25
• Percentage increase = 0.25 × 100 = 25%

So moving from 80 to 100 is a 25% increase.

Real-world uses of percentage increase

1) Personal finance

If your monthly income rises from $4,000 to $4,400, your increase is $400. Percentage increase gives the cleaner comparison:

((4,400 - 4,000) / 4,000) × 100 = 10%

2) Investing

A stock goes from $50 to $65. Dollar gain is $15, but percentage increase is:

((65 - 50) / 50) × 100 = 30%

3) Business metrics

Website traffic goes from 10,000 visits to 12,500 visits. That is:

((12,500 - 10,000) / 10,000) × 100 = 25%

Percentage increase vs percentage points

These are often confused:

• Percentage increase compares relative growth. Example: from 10% to 12% conversion rate is a 20% increase because 2/10 = 0.20.
• Percentage points is an absolute difference between percentages. Example: from 10% to 12% is a 2 percentage-point increase.

Both can be correct, but they mean different things.

Common mistakes to avoid

• Using the new value as the denominator: always divide by the original value.
• Forgetting to multiply by 100: 0.18 is 18%, not 0.18%.
• Ignoring sign: if the result is negative, it is a decrease, not an increase.
• Rounding too early: round only at the final step to improve accuracy.
• Using original value = 0: percentage increase is undefined in standard math because division by zero is not allowed.

How to calculate new value from a percentage increase

Sometimes you already know the original value and the rate of increase, and you want the future value.

New Value = Original Value × (1 + Percentage/100)

Example

Original = 250, increase = 12% New Value = 250 × (1 + 12/100) = 250 × 1.12 = 280

How to calculate original value from new value and increase

If you know the new value and the increase rate, solve backwards:

Original Value = New Value / (1 + Percentage/100)

Example

New value = 560, increase = 12% Original = 560 / 1.12 = 500

Quick mental math tips

• 10% is easy: move decimal one place left.
• 5% is half of 10%.
• 1% is 10% divided by 10.
• For rough estimates, combine simple chunks (e.g., 12% ≈ 10% + 2%).

Final takeaway

Calculating percentage increase is one of the most practical math skills you can learn. The key is to always compare the change to the original value. Once you memorize the formula, you can analyze growth confidently in budgeting, investing, pricing, and performance tracking.

Use the calculator above anytime you need a fast and accurate answer.