Percentage Change Calculator
Enter your old and new values to instantly calculate the percentage change — whether it is an increase or decrease. Free, fast, and no signup required.
What Is Percentage Change?
Percentage change measures how much a value has increased or decreased relative to its original amount, expressed as a percentage. Unlike percentage increase or percentage decrease calculators that only handle one direction, a percentage change calculator automatically determines whether the value went up or down and shows the result with the correct sign.
A positive percentage change means growth (increase), while a negative percentage change means decline (decrease). For example, if your monthly sales went from $10,000 to $12,500, the percentage change in sales is +25%. If they dropped to $8,000, the percentage change is −20%.
Percentage change is one of the most widely used calculations in business, finance, science, and education. It is the foundation of year over year percentage change reports, percentage change in price analysis, economic growth metrics, and scientific measurements like percentage change in mass. Whenever you need to compare a "before" and "after" value, percentage change is the right tool.
How to Calculate Percentage Change
The percentage change formula is simple. You need two numbers: the old value (starting point) and the new value (ending point).
Step-by-Step Instructions
Step 1: Find the difference. Subtract the old value from the new value. If positive, the value increased; if negative, it decreased. Example: old = 80, new = 100, difference = 20.
Step 2: Divide by the old value. This converts the change into a decimal. 20 ÷ 80 = 0.25.
Step 3: Multiply by 100. Convert to a percentage. 0.25 × 100 = 25%. The value changed by +25%.
Key difference: If you already know the direction of change, use our specialized tools: Percentage Decrease Calculator for declines, or Percentage Increase Calculator for growth.
How to Calculate Percentage Change in Excel
The percentage change formula excel is one of the most commonly searched formulas. Put the old value in cell A1 and the new value in B1:
Format as a percentage. This percentage change formula in excel works for any pair of values. To calculate percentage change in excel for multiple rows, drag the formula down. The same percentage change formula google sheets works identically.
To calculate percentage change between two numbers in excel against a fixed baseline, use an absolute reference: =(B2-$B$1)/$B$1. This is especially useful for calculating year over year percentage change or tracking percentage change in price over multiple periods. You can also find percentage change in excel by creating a percentage change chart — select your data and insert a line chart with percentage-formatted Y-axis.
When Do You Need a Percentage Change Calculator?
Percentage change is used whenever you compare two values over time. Here are the most common scenarios:
Sales & Revenue
Track percentage change in sales month-over-month or quarter-over-quarter for business reporting.
Pricing & Inflation
Calculate percentage change in price to understand cost shifts in economics and consumer budgeting.
Year-Over-Year
Calculate year over year percentage change for annual reports and performance benchmarking.
Science & Lab
Measure percentage change in mass during experiments, chemical reactions, or material testing.
Education
Solve percentage change questions in math class, standardized tests, and academic assignments.
Personal Finance
Track changes in salary, rent, investments, utility bills, or any personal metric over time.
Percentage Change Examples
Click any example to see the full calculation. These include both increases and decreases.
Real-World Percentage Change Examples
Price change: A subscription increases from $9.99 to $14.99/month. The percentage change in price is ((14.99 − 9.99) / 9.99) × 100 = 50.05%. Knowing the exact percentage helps you evaluate the value.
Sales change: Quarterly revenue went from $180,000 to $225,000. The percentage change in sales is ((225,000 − 180,000) / 180,000) × 100 = 25% growth.
Mass change: A sample's mass changed from 12.5g to 11.8g after heating. The percentage change in mass is ((11.8 − 12.5) / 12.5) × 100 = −5.6%. The negative sign confirms mass was lost.
Detailed Worked Example: Year-Over-Year Change
Your company earned $2.4M in 2024 and $3.0M in 2025. To calculate year over year percentage change:
Step 1: Difference = $3,000,000 − $2,400,000 = $600,000
Step 2: Divide = $600,000 ÷ $2,400,000 = 0.25
Step 3: Multiply = 0.25 × 100 = +25%
Revenue grew 25% year over year. In Excel: put 2400000 in A1, 3000000 in B1, use =(B1-A1)/A1.
Percentage Change vs. Other Calculations
Percentage change is often confused with similar calculations:
Percentage Change vs. Percentage Increase
Percentage increase only measures growth. Percentage change handles both growth and decline. If unsure of direction, use percentage change.
Percentage Change vs. Percentage Decrease
Percentage decrease only measures decline. Percentage change gives the same result but with a negative sign for decreases.
Percentage Change vs. Percentage Difference
Percentage difference compares two values without a defined direction, using their average as the base. Percentage change has a clear "before" and "after" relationship.
Frequently Asked Questions
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