How To Calculate Percentage Increase & Decrease With Our Free Calculator

Calculate percentage increases, decreases, and ratios with our comprehensive percentage calculator suite. Perfect for finance, marketing, and everyday calculations.

Use this tool to quickly find percentage changes, what percentage one value is of another, and what percent one value is of a second value.

To fully understand how to calculate Percentage change we reference the comprehensive guide on OMNICalculator. This ensures our calculation methodology aligns with industry-recognized best practices.

Increase/Decrease

Calculate percentage change between two values

Percentage Change

Enter values to see percentage change

Percentage Change

Formula: ((New Value - Original Value) / Original Value) × 100

Use this to calculate the percentage increase or decrease between two values.

Positive results indicate an increase, negative results indicate a decrease.

Percentage Of

Formula: (Part Value / Total Value) × 100

Find what percentage one number represents of another number.

Commonly used for calculating proportions and ratios.

What Percent

Formula: (X / Y) × 100

Calculate what percentage X represents of Y.

Similar to "Percentage Of" but with different input labeling for clarity.

Common Use Cases

Business & Finance

Calculate profit margins, revenue growth, expense reductions, and financial performance metrics.

Marketing Analytics

Measure campaign performance improvements, conversion rate changes, and audience engagement growth.

Academic & Research

Analyze data changes, calculate survey response rates, and measure statistical improvements.

Everyday Calculations

Calculate discounts, tips, tax amounts, and compare prices or quantities in daily life.

The Complete Guide to Percentage Calculations

A percentage calculation is a very simple way to express a number as a fraction. It is often used to compare two numbers or to express a part of a whole. Percentages are commonly used in various fields such as finance, statistics, and everyday life.

For our sake here, whether you are tracking the growth of your companies revenue, identifying whether your engagement has increased or monitoring the drop in CPC, percentage increase and decrease are a universal language, we can use to measure change over time.

Understanding how to calculate percentage increase and decrease allows you to interpret raw data and put it into meaningful context, for you, your team, or your clients. For instance, knowing your CPM has increased from $5.00 to $5.50 is not as immediately impactful as knowing that represents a 10% increase to your overall cost of advertising.

The suite of calculators here are designed to immediately handle all three common use cases you might require when working on your day to day analysis or reporting. They are, finding the change between two numbers, finding the par of a whole and finding what percent one number is of another.

How to Calculate Percentage Change Manually

To calculate percentage change manually, you can follow these steps:

  • Find the Difference: Subtract the original value from the new value. Example: Last month's revenue (Original Value) was $5,000. This month's revenue (New Value) is $6,500. Difference: $$6,500 - $5,000 = $1,500
  • Divide by the Original Value: Divide that difference by the starting value. This gives you the change as a decimal. Example of this is: $1,500 / $5,000 = 0.3
  • Multiply by 100: Multiply the result by 100 to convert the decimal into a percentage. Example: $0.3 * 100 = 30%.
  • A positive result 30% indicates a percentage increase. If the result were negative, it would indicate a percentage decrease.

Frequently Asked Questions (FAQ) & Common Misconceptions

Can a percentage be over 100%?

Yes. If the New Value is more than double the Original Value (e.g., an increase from 50 to 150), the percentage change will be over 100%. This simply means the value has more than doubled.

What is a percentage point?

A percentage point is the difference between two percentages. For example, if your Conversion Rate goes from 5% to 7%, that is a 2 percentage point increase, not a 2% increase. The actual percentage increase is 40% (since 7 is 40% greater than 5).

Is it safe to round up when dealing with percentages?

In most financial and marketing calculations, it's best to use at least two decimal places (e.g., 15.25%) for accuracy. This is why our calculator shows everything to two decimal places for you already.

Why is the Original Value not allowed to be zero?

In the Percentage Change formula, the Original Value is in the denominator. Dividing by zero is mathematically undefined, meaning a percentage change from zero is impossible to calculate.