What are the Values of "Machine Constants" in Excel/VBA? The Fortran code for TOMS Algorithm 691 refers to five "machine constants" belonging to the host computing environment. Two of these are: 1. "The smallest relative spacing", given as "B ** (-T)", where B = base (say 10?), and T = number of base-B digits, say 15, so this = 10**-15...? 2. "The largest relative spacing", given as "B**(1-T)", so this = 10**(1-15) = 10**-14...? It appears the values are being used in the program for fine-grain error management. Unfortunately, I can find no general references to these constants, and I'm not certain what they mean, nor what their values are... Would anyone be able to enlighten me on the particular values of these two parameters for the Excel/VBA environment. TIA for any assistance.