how to calculate increase percentage

Quick answer

To calculate increase percentage, subtract the original value from the new value, divide by the original value, then multiply by 100.

Step-by-step: how to calculate increase percentage

1) Find the difference

Start by finding how much the value changed in total:

Difference = New Value - Original Value

2) Divide by the original value

Take that difference and divide by the original (starting) amount:

Difference ÷ Original Value

3) Convert to a percentage

Multiply by 100 to convert the decimal to a percentage:

(Difference ÷ Original Value) × 100

Examples you can follow

Example 1: Price increase

A product rises from $80 to $100.

• Difference: 100 - 80 = 20
• Divide by original: 20 ÷ 80 = 0.25
• Convert to percent: 0.25 × 100 = 25%

Example 2: Salary increase

Your salary goes from $50,000 to $56,000.

• Difference: 56,000 - 50,000 = 6,000
• Divide by original: 6,000 ÷ 50,000 = 0.12
• Convert to percent: 0.12 × 100 = 12%

Example 3: Website traffic growth

Monthly visitors increase from 12,000 to 15,000.

• Difference: 15,000 - 12,000 = 3,000
• Divide by original: 3,000 ÷ 12,000 = 0.25
• Convert to percent: 0.25 × 100 = 25%

Reference table

Original	New	Absolute Increase	Percentage Increase
40	50	10	25%
120	150	30	25%
200	260	60	30%

Common mistakes to avoid

• Using the new value as the denominator: always divide by the original value when calculating increase percentage.
• Forgetting to multiply by 100: without this step, you'll get a decimal instead of a percentage.
• Confusing percentage points with percent increase: they are not the same thing.

Percent increase vs. percentage points

Suppose an interest rate rises from 4% to 6%:

• The increase is 2 percentage points (6% - 4%).
• The percent increase is 50% because 2 ÷ 4 = 0.5, and 0.5 × 100 = 50%.

Both numbers are useful, but they communicate different meanings.

What if the result is negative?

If your new value is lower than the original value, the formula returns a negative percentage. That means a percentage decrease, not an increase.

FAQ

Can I calculate increase percentage with decimals?

Yes. The same formula works with decimals, money, units sold, and most measurable values.

Why can't I divide by zero?

Division by zero is undefined, so if the original value is 0, a standard percentage increase cannot be calculated in the usual way.

How accurate should I round?

For most practical uses, rounding to 2 decimal places is enough. Financial or scientific contexts may require more precision.

Final takeaway

Calculating increase percentage is simple once you remember the core formula: subtract, divide by the original, and multiply by 100. Use the calculator above for quick checks, and follow the worked examples whenever you need to verify your math.