Data Curve Fit Creator Add-in is an easy-to-use data analysis add-in for Microsoft Excel. It adds curve fitting, interpolation, and data smoothing functions to Excel.

Curve fitting functions include polynomial fits and a versatile local regression (loess) function. Interpolations include linear, cubic spline, and a 'flexible spline' that allows you to specify the slope at each data point.

Data smoothing functions include moving average, median filter, and a Gaussian smoothing filter.