Percent Increase Calculator: Formula & Examples

This calculator works out the percentage increase from an original number to a new number. You enter the starting value and the final value, and it returns the percent change, along with the absolute difference. The result tells you how much the value grew relative to where it started, expressed as a percentage.

Formula

The percent increase is calculated with this formula:

Percent Increase = ((New Value − Original Value) ÷ Original Value) × 100

Where:

• Original Value – the starting number (before the change)
• New Value – the number after the increase
• Percent Increase – the relative growth, expressed as a percentage

If the new value is smaller than the original, the result is negative, which indicates a percentage decrease. The absolute difference (New − Original) is also shown for reference.

Worked Example

Using the default values: Original = 50, New = 75.

1. Subtract the original from the new: 75 − 50 = 25
2. Divide by the original: 25 ÷ 50 = 0.5
3. Multiply by 100: 0.5 × 100 = 50%

The percent increase is 50%. The absolute increase is 25. This matches the calculator output for the default inputs.

When to Use a Percent Increase Calculator

Percent increase is used whenever you want to express growth relative to a starting point. Common situations include:

• Comparing salary raises or price changes
• Measuring population growth or sales growth
• Tracking investment returns (though compound growth is different)
• Evaluating test score improvements or fitness progress

The key is that the original value is the baseline. A change from 10 to 20 is a 100% increase, while a change from 100 to 110 is only a 10% increase, even though both add 10 units.

How to Read the Result

A positive percent increase means the new value is larger than the original. For example, a 50% increase means the new value is 1.5 times the original. To verify, multiply the original by (1 + percent/100): 50 × 1.5 = 75.

A result of 0% means no change. A negative result means a decrease; the magnitude tells you how large the decrease is relative to the original. For instance, a drop from 80 to 60 is a −25% change.

Common Mistakes and Misconceptions

• Reversing the order: Always divide by the original value, not the new value. Dividing by the new value gives a different number and is not the percent increase.
• Confusing percentage points with percent: If a rate goes from 4% to 6%, that is a 2 percentage point increase, but a 50% increase (2 ÷ 4 × 100). The two are not the same.
• Rounding too early: Round only at the final step to avoid errors. For example, (1/3) × 100 = 33.33%, not 33% if you round 0.333 first.
• Ignoring units: The formula works with any units as long as both values use the same unit. Mixing dollars and cents, or meters and kilometers, will give a wrong result.

Limits of the Formula

The percent increase formula assumes a simple, one-step change from an original to a new value. It does not account for:

• Compound growth over multiple periods (use compound interest formulas instead)
• Negative original values (the formula can produce misleading results; e.g., from −10 to 20 gives −300%)
• Changes where the baseline is zero (division by zero is undefined)

For multi-period growth, you would calculate the compound annual growth rate (CAGR), which is a different formula. For negative baselines, the percent change is not meaningful in most contexts.

Frequently Asked Questions

How do I calculate percent increase without a calculator?

Subtract the original from the new, divide that difference by the original, then multiply by 100. For example, from 40 to 60: (60−40) ÷ 40 × 100 = 50%.

What is the difference between percent increase and percentage point increase?

Percent increase is a relative measure (how much bigger relative to the original). Percentage points are the absolute difference in percentage values. If a rate goes from 10% to 15%, that is a 5 percentage point increase, but a 50% increase.

Can percent increase be negative?

Yes. If the new value is less than the original, the formula gives a negative number, which represents a percent decrease. For instance, from 80 to 60 is −25%.

What if the original value is zero?

Division by zero is undefined, so the percent increase cannot be calculated. In such cases, you can only describe the absolute change (e.g., “increased by 5”) rather than a percentage.

How do I convert a percent increase back to the new value?

Multiply the original value by (1 + percent/100). For a 25% increase on 80, that is 80 × 1.25 = 100.

Is percent increase the same as percent change?

Percent change is the general term. Percent increase specifically refers to a positive change. The formula is identical; the sign of the result tells you whether it is an increase or decrease.

Related

• Unit Learning Curve Calculator: How to Use It
• Test Curve Calculator: Grade Scaling Explained
• Time Curve Calculator: Pace, Speed & Duration

in a | Original value | - | 50 | 0
in b | New value | - | 75 | 0
out pct | Percent increase | % | (b - a) / a * 100 | 2
out diff | Absolute increase | - | b - a | 2