Online Curve Fitting and Regression Analysis Tool

For advanced multivariable nonlinear regression, use ndCurveMaster — it automatically discovers complex equations with many input variables, like:

Y = a₀ + a₁·x₁^-5 + a₂·sin(x₂)^-1.3 + a₃·1/4^x₃ + a₄·x₄^-0.2 + a₅·ln(x₅)² + a₆·exp(x₆)² + a₇·cos(x₂)^1/2·ln(x₃)·x₆^-1/3

Download the free trial.

For complex curve fitting with a single independent variable, you can use ndCurveMaster 2D (free desktop version). For simpler tasks, this online curve fitting tool runs directly in your browser and requires no installation.

This online regression calculator is completely free, requires no login, and works instantly without installation. It supports the following regression models:

• Linear Regression
• Polynomial Regression (degrees 2 to 5)
• Exponential Regression
• Exponential Model (a + b * e^−cx)
• Logarithmic Regression
• Power (log-log)
• Gaussian (Bell Curve) Regression
• Michaelis-Menten Kinetics
• 4PL and 5PL Logistic Regression

Each model includes detailed regression metrics such as R² (coefficient of determination), MSE (mean squared error), MAE (mean absolute error), and RMSE (root mean square error).

The tool automatically generates regression plots for visual analysis and model comparison. Whether you're performing curve fitting online or running a complete regression analysis, this tool helps you find the best-fit model with ease.

Paste x and y values below to calculate results instantly.