Exponential Regression Calculator

About this tool

What Is exponential regression? Exponential Regression Calculator. The exponential regression calculator fits a curve of the form y = a·e^(b·x) to your points and uses it to forecast new values. It is the standard model for population growth, compound decay, and viral curves. Exponential regression models data that grow or decay by a constant percentage per step. Taking logarithms turns the model into a straight line, which is exactly how the tool estimates a and b by linear least squares on ln(y). The coefficient a is the value at x = 0, and b is the continuous growth rate: b > 0 means growth, b < 0 decay. ln y = ln a + b·x, then back-transform to y = a·e^(bx). How to Use Add rows with matching x and y values. All y must be positive for the log transform. Enter the data, adding as many rows as you need. Read the fitted equation y = a·e^(bx), the R² fit quality, and any predictions you request. Worked Example Doubling data (0,1), (1,2), (2,4), (3,8) fits y = 1·e^(0.693x), where b ≈ 0.693 is ln 2. Predicting at x = 4 returns 16, exactly the doubling law. Common Use Cases population and epidemic projection compound interest trend fitting radioactive decay experiments algorithm growth scaling Important Notes All y-values must be strictly positive because the method logs them. R² closer to 1 means a tighter fit. Everything runs locally in the browser. Related Tools Polynomial