Paul, that's very interesting, I've never worked with such large numbers. I've been told that FoxPro has problems no matter what you do with extremely large numbers, especially with numbers much larger than what you're using now. However, the Double data type is made for this circumstance. You can try it, but I'd compare the results with Excel even with the Double data type. maybe you'll have to develop a way of getting the calc done outside of FoxPro and then bringing it back into FoxPro.

Wally