Step 1: Determine your available space
If you have a huge open wall, you will want to work around your furniture using the general rule of covering 2/3 to 3/4 of that area with your artwork. But if you have a small bare wall (like in a hallway or between two windows), you can keep the space a little more open by using the next step.
Step 2: Do a little math
One guideline is to leave 3/8 of the width of your art on each side of your area. Got that? You may have to read it again (we did!). Here's another way to look at it: The art should take up 4/7 of the selected space. Since this isn't a fraction we see very often (if at all), use this math trick to get the size art you need: multiply your wall space (in inches) by .57 (4/7 turned into a decimal). So say your area is 36 inches -- you want to look for art that's 20-21 inches wide. Easy, right?
Step 3: Go shopping
Now that you know what size you're looking for, have fun with it. And honestly, if you're a little over or under, no one will notice, as long as the piece is centered.
Step 4: Start hanging
When you get out your nails and hammer, keep in mind that in most open spaces the center of your art should be approximately eye-level (the average is 60 to 65 inches from the floor). But in the dining room and living room (and other places you sit), hang the art a little lower, still keeping the bottom edge of the frame 6-12 inches above a sofa, tabletop, or chair rail.
Hanging one large piece draws attention to a focal point in the room, like a fireplace or bed, and sets a more formal tone. If just one piece looks too tiny on the wall (especially in a narrow space), hang a vertical series of pieces of the same size. (Groupings of three and five create a natural center.) To unify them, keep the space between the pieces equal, even if the frames are different sizes.
DIY project ideas from the experts at The Nest
Sources: Room Redux, The Home Decorating Workbook; HGTV.com; Math by Danny Isquith