I am trying to derive a nominal value from a Mathcad result using nested IF functions. I can do this in Excel but am not clear on how, or if, this is possible in Mathcad. Has anyone tackled this issue and can offer some much appreciated assistance?

Here is original formula:
tbh:= (P + PAs) * OD / (2 * Sbh * Eh) + (1.8 * (P + PAs))

where, P=150 psi; PAs=0 psi; OD=96 in; Sbh=20000; Eh=1

Here is Mathcad result:
tbh = 0.357586 * in

Here is Excel function formula trying to replicate in Mathcad:
IF((tbh+0.0625)<=0.25,0,0.25,IF(tbh+0.0625>0.25,((ROUNDUP(tbh*16,0))+1)/16,"Error"))

Here is desired result: tbh_nom = 7/16 * in (fractional with units is desired output)

Thanks in advance for your help...