I'd start there. Their activity multipliers are crap, so I'd take the BMR and add about 500 calories to it and see how that works for a few weeks.
Be ware, not following a good program is a good way to spin you wheels and not get anywhere. I'd recommend following 70sbig to a tee.
Also what is your immediate goal? If it's to get strong and fast using a program like 70sbig you need to eat to support the training but you might add a few pounds of "bulk" on.