And my Liberal; Arts is showing, because after ALL that balderall, I forgot to do the simple calculation of: 1 / 0.57142857142857142857142857142857 which, LO!, equals 1.75. Duh. SO, after using this to calculate Base for a given pip count X: Base = (Base of X-1) + 0.21875 Height = 1.75 * Base I had a feeling I was tan(arctan(foo)) somewhere, and there it is. *brain starting to swell... and leak out ears* David