Hello. I have tried your deflection calculation and cannot get the same results as I get in other calculators. It seems your deflections are 10 times too high. you do not put your units in so it is hard for me to confirm which calculator is right. I believe the issue is with your conversion of I. For instance: simple beam deflection calculation. for the 40x40 beam I= 81.407 cm^4 (i assume units) Your speadsheet converts this to Inertia on X : 8.141E-08 m^4 (i assume units again) my conversion would be to 8.14E-07 m^4 or 81.4E-08 Am I missing something??