Curve Fitting Tool

Enter your data as (x, y) pairs, choose the model (Linear, Log, Power, Exponential), or enter your own function, to find the curve that best fits the data.

How to Use It

• Enter Your Data: Type coordinates into the text box in (x,y) format. For example: (2,4), (5,9), (8,7)
• Choose a Model: Select from the dropdown menu and press "Set", or type in your own function! Common models include:
  • Linear: Best for a straight-line relationship
  • Logarithmic (Log): Best for data that increases quickly at first but then levels off
  • Exponential: Best for rapid growth (where the rate of change keeps increasing)
  • Power: Best for relationships where one variable is proportional to a power of another (like area vs. radius)
• Find the Best Fit: Manually move the a and b sliders to see if you can minimize the total error (Σd²). This is fun to play with!
• Zoom and Reset change the extents of the graph

What's Σd²?

The value Σd² (Sum of Squares) represents the total "error" of your line.

The vertical lines on the graph show the residual (the distance) between each point and the line. By squaring these distances and adding them up, we get a single number that tells us how well the line fits the data. The lower the number, the better the fit!