Introduction
Year over year (YoY) growth tells you how much a number has changed compared to the same period one year ago. It is one of the most common ways businesses track progress. Whether you look at revenue, profit, users, or sales, YoY growth shows you the real trend by cutting out seasonal ups and downs.
This Year Over Year Growth Calculator does the math for you in seconds. Enter your values for two or more years, and the tool finds the percentage change for each period. You can compare up to 10 metrics side by side, view step-by-step solutions, and see your results on clear charts. If you want to look ahead, switch to the Forward Projection tab to estimate future values based on a target growth rate.
Use this calculator to spot growth, catch declines early, and make smarter decisions backed by data.
How to Use Our Year Over Year Growth Calculator
Enter your values for two or more time periods, and this calculator will show you the year over year (YoY) growth rate, absolute change, and trend direction for each metric. It works in two modes: Standard YoY Growth and Forward Projection.
Standard YoY Growth
Metric Label: Type a name for what you are measuring, such as "Revenue" or "Active Users." You can edit this label at any time by clicking on it in the table.
Year Labels: Each column stands for one time period. Edit the label at the top of each column to match your actual years, like "2024" or "Q1 2025."
Values: Enter the number for each metric in each year. These can be positive, negative, or decimal numbers. For example, type 50000 for fifty thousand in revenue.
Add Year: Click this button to add more time periods to compare. You can add up to 10 year columns. You need at least 2.
Add Metric Row: Click this button to track another metric side by side. You can add up to 10 metric rows.
Press Calculate to see your YoY growth rates, a summary table, detailed breakdowns, step-by-step math, and charts.
Forward Projection
Metric Label: Enter a name for what you want to project, such as "Revenue" or "Users." This label is optional and helps identify your results.
Base Value: Enter your known starting value. This is the number you want to grow or shrink from.
Target YoY Growth Rate (%): Enter the annual growth rate you want to apply. Use a positive number for growth or a negative number for decline. For example, enter 10 for 10% growth per year.
Years to Project: Enter how many years into the future you want to project. You can choose any whole number from 1 to 50.
Press Calculate Projection to see your projected future value, total growth over the full period, a year-by-year table, step-by-step formula, and a growth chart.
What Is Year Over Year Growth?
Year over year (YoY) growth measures how much a value has changed compared to the same period one year earlier. It is shown as a percentage. If your revenue was $50,000 last year and $55,000 this year, your year over year growth rate is 10%. A positive number means growth. A negative number means decline.
How to Calculate Year Over Year Growth
The formula is simple. Take your current year value, subtract the prior year value, then divide by the prior year value. Multiply the result by 100 to get a percentage.
YoY Growth Rate = (Current Value − Prior Value) ÷ Prior Value × 100
For example, if a company earned $80,000 this year and $64,000 last year, the math looks like this: ($80,000 − $64,000) ÷ $64,000 × 100 = 25%. That means earnings grew by 25% year over year. If you need to find the percentage increase or percentage decrease between any two values, those dedicated tools can help as well.
Why Year Over Year Growth Matters
YoY growth is one of the most common ways businesses track performance over time. It helps you see real trends by comparing the same time frames, which removes the effect of seasonal ups and downs. A retail store, for instance, always sells more in December. Comparing December to November would be misleading. Comparing this December to last December gives a much clearer picture.
Investors, business owners, and analysts use year over year growth to evaluate revenue, profit, customer lifetime value, website traffic, and many other key metrics. Pairing YoY growth with your ROI gives you an even fuller view of business performance. Steady YoY growth usually signals a healthy business. A declining rate can be an early warning sign that something needs to change. Businesses also use tools like a break even calculator and a margin calculator alongside growth analysis to understand profitability from multiple angles.
What Is Forward Projection?
A forward projection uses your current value and an assumed growth rate to estimate what a number could look like in future years. It applies compound growth — closely related to what a CAGR calculator measures — meaning each year's growth builds on the previous year's total, not just the original amount. This is the same idea behind compound interest. Even a small annual growth rate can lead to large gains over many years. You can use the Rule of 72 as a quick way to estimate how many years it takes for a value to double at a given growth rate.
Key Things to Keep in Mind
- A prior value of zero makes the formula undefined. You cannot divide by zero, so YoY growth cannot be calculated when the starting value is zero.
- Negative values are allowed. If a business goes from a loss of $10,000 to a loss of $5,000, the calculator will still show the percentage change.
- YoY growth does not explain why something changed. It only shows how much. You still need to look at the reasons behind the numbers.
- Projections are estimates, not guarantees. Real-world results depend on market conditions, competition, and many other factors that a formula cannot predict. For more rigorous financial forecasting, consider using an NPV calculator or a DCF calculator to account for the time value of money.