estimated abv and measured abv don't match

Using Build 46 on OSX 10.6.8 and also Vista Home Premium.  This problem occurs on both machines.

When working on a recipe, on the right, I tweaked the stuff shown and have "measured abv" also showing there, in addition to the "est abv" that's showing on the left under color.  With recipes where the numbers are the same for OG and FG in the estimated and measured areas, sometimes the abv is not the same in both sections.  Sometimes one is higher, sometimes the other.  I've only seen it off by .1% thus far.  Sometimes it does match, but more often it does not.

Not a huge problem, obviously.  But seems a bit weird.  If the OG and FG are the same in both sections, the alcohol calculated should also be the same.

This problem also exists with version 1.4.

Hi,
  The likely cause is the rounding precision of the OG/FG measurements.  The estimated OG are calculated internally to double precision and then rounded off when displayed on the screen.  However the actuals are rounded first (the OG and FG inputs) and then the calculation is done.

  Since the inputs are rounded in the "actual case" and not rounded for the estimates, it will result in a slightly different value for the final calculation.

Brad

Ah, okay.  Thanks for the info, Brad.

Brad,
Could my estimated ABV and measured ABV be off as much as 4%?  My recipe is showing 8.7% Est ABV and 4.7% Measured ABV for an Imperial IPA

Thanks