Calculate and Cut Rafter Plumb and Seat Cuts

either can calculate from the top of your ledger or the top of your beam. I know it's 7-ft from the outside of the beam, so this is how I'll make my calculation for my rafters. We'll mark down from the top of our ledger and we'll mark the top of our rafter, which is 20 and 5/8, and then we'll subtract the height above plate, which is 4 and 3/4, and that gives us the top of our beam. The height above plate is just from the bottom of the seat cut to the top of the rafter. Then we'll make a level mark down from our outside rafter, and then we'll level and install a temporary brace. You can measure up from your post base to determine beam height, or you can set a laser on the structure and use that. The top of beam height that we determined is if you have no seat cut on your rafter, but if you add a seat cut, this beam will actually have to be raised from that distance, so the rafter doesn't actually change at all. The beam height is actually what needs to change. All you need to do is take your plumb cut and add this number to your post size. Just be sure when you cut your post, you subtract for the height of your beam. For our post, we'll just mark it out to the height of our beam. Now we're going to subtract our beam height, which is 7 and a quarter. We'll measure down on the post and make that mark, and then we'll add our rafter's plumb cut. This is the top of the beam. The beam sits all the way down to this mark, but we'll add for our seat cut. This mark can change depending on the height of your plumb cut. Say this plumb cut was higher at like an inch and a half, you would just add that to this post, and that would make up for the difference. If your post isn't