Is there any way to have excel find values on a curve for you? I have plotted a curve with a y-axis representing area, and an x-axis representing depth in feet. (working towards the volume of a lake) Currently I have values for the x-axis in three foot segments (eg. Surface area at 3ft = 15000 sqft) What I really want to know is what is the surface area at 1.5 ft. Is there any way excel can detemine values (area in this case) for points that I do not have data for?