Rebar Size to Structural Load Estimator Select Rebar Size: -- Choose a Rebar Size -- #3 (0.375 inch diameter) #4 (0.500 inch diameter) #5 (0.625 inch diameter) #6 (0.750 inch diameter) #7 (0.875 inch diameter) #8 (1.000 inch diameter) #9 (1.128 inch diameter) #10 (1.270 inch diameter) Estimate Load Capacity Download PDF