STAAD Foundation Effective Depth Calculations


I am designing an isolated footing in SFA. I just want to clarify some things with regard to the calculations used by the software:

1) In the shear calculation, the calculated effective depth does not match hand calculation. Hand calculation shows 0.165m but SFA solved it to be 0.1655m (Example from Isolated Footing 1). Through back calculation, I found that SFA uses 9.5mm for the reinforcement steel diameter instead of 10mm. Why is it that STAAD uses 9.5mm diameter when I have selected a 10mm steel diameter size from the design menu? Why wasn't this updated by the software developers?

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