The rule is simple, you hang your artwork in your home so that the center is 57" off the ground, an average for eye-level. This gives harmony to all the pieces in your home visually, helps you curate a cohesive collection, and allows visitors to view each piece with the same ease they'd view artwork in a gallery.
The Formula is thus: Measure the height of the art piece, then divide this in half. Add this amount to 57". Measure the distance from the taut wire or hook in the back to the top of your art piece. then subtract that amount from the total and this is where you'll add your nail to the wall to hang your piece at perfect eye-height.
Artwork height divided in half + 57 - Distance from hook to the top of art
The same formula applies for an art grouping. Arrange the collection on the floor first, then measure this grouping from the top to the bottom. Divide that number in half to hang the whole group at eye-height.
My brain shut down, as it always shamefully does, when I saw the math. But when you put it into practice it's alarmingly simple. Be Not Afraid. Today I'm going to use the formula to finish hanging everything at eye level. This is perfect for my space that doubles as a back-drop for product photography as I live and work here. I firmly believe rules are meant to be broken for unique spaces but I like strictly following this one for harmony.
Got any further picture-hanging apartment-harmony-making tips? How do you go about hanging pieces perfectly? Before this I really did just go about it blindly trusting my eye to keep it harmonious.