Thanks, Martín and Vlad.

Martín :
I can't see the file ("GenRepoX"), it gives a error if i trie to download.

Vlad:
Thanks, for the tip, but at this point, but i need the EXACT formula to calculate the size of the Field in "Fox Report".

See the example:

Font | Form | Report | My Formula
---------------+--------+------------+-----------------
Arial 4 | 8 | 625.000 | 625.000 |
9 | 17 | 1562.500 | 1562.500 |
18 | 29 | 2916.667 | 2916.667 |
24 | 38 | 3854.167 | 3750.000 | ????

The Values from de "FORM" and "REPORT" was given by de VisualFoxPro
I get a formula that gives the correct result for ALLMOST sizes and Fonts

---------------------------------------------------------------------------
Function GetTextHeight
Parameter tcFontName, tnFontSize
#define g_RptConverteFACTOR 104.166666666667

Local lnSize
lnSize = FONTMETRIC(1, tcFontName, tnFontSize)
lnSize = Round(lnSize * g_RptConverteFACTOR, 3)
Return lnSize
---------------------------------------------------------------------------

Nuno Brito