Depth is the shelf measurement people think about least and regret most. Length is obvious, it is the wall. Height you can adjust by eye. Depth is a single number chosen once, and if it is wrong the shelf is either useless or in the way.
The short answer, before the detail: most rooms want 6 to 10 inches. Kitchens want more. Hallways want less. Almost nobody needs 14.
The general rule: depth follows the deepest thing you will put on it
Not the biggest thing you own. The deepest thing that will live on this particular shelf, plus about an inch so it is not hanging over the front edge.
Useful reference depths:
- Paperback books: 5 inches
- Hardback books: 6 to 7 inches
- Dinner plates, stacked: 11 inches
- Cereal bowls and mugs: 6 to 7 inches
- Framed 8x10 photo, leaning: 4 inches
- A record sleeve: 12.5 inches
- A typical potted plant: 6 to 8 inches
Living room: 8 to 10 inches
This is the do-everything depth. It takes hardbacks standing upright, a leaning frame in front of them, a small plant and a bowl, all at once, with the front edge still clear. For arranging that mix, see how to style floating shelves.
Go to 6 inches if the shelf is purely decorative and you want it to almost disappear into the wall. Go to 10 if it sits above a sofa and needs to hold proportion against a large piece of furniture.
Above a television, 8 inches is usually enough and looks lighter than 10.
Kitchen: 11 to 12 inches
The kitchen is the one room where you genuinely need the depth, and the number is set by dinner plates. A standard dinner plate is 10.5 to 11 inches across. A 10-inch shelf leaves the stack overhanging, which looks wrong and is worse than it looks, plates knocked from the front edge come down on a hard floor.
12 inches is the safe kitchen depth. It matches the depth of most upper cabinets, so open shelving lines up with whatever cabinetry is left in the room, and it takes plates, bowls, glasses and a small appliance.
If you are only holding mugs, glasses and spice jars, 8 inches is plenty and keeps the room feeling wider.
Bathroom: 6 to 8 inches
Bathrooms are tight and the things on the shelf are small, bottles, folded towels, a candle. 6 inches handles all of it. 8 inches if you are stacking bath towels rather than hand towels. More ideas for a tight bathroom are in the small bathroom storage guide.
Above a toilet, do not go past 8 inches. Past that you will hit your head standing up, and everyone eventually does.
Bedroom: 6 to 8 inches, or 10 to 12 as a bedside shelf
A decorative shelf above a bed or dresser wants 6 to 8 inches, enough for frames, a small plant, a stack of books.
A floating shelf used instead of a nightstand is a different object and needs 10 to 12 inches, because it has to take a lamp, a glass of water, a phone and a book without any of them at the edge. Look at the floating shelves in that depth range if that is what you are replacing.
Hallway and entryway: 4 to 6 inches
The constraint here is not what the shelf holds, it is your shoulders. In a corridor under about 42 inches wide, anything deeper than 6 inches gets caught on coats and bags every time somebody walks past.
4 inches holds keys, post and a small tray, which is the entire job.
Home office: 8 to 10 inches
Above a desk, 8 inches keeps binders, books and a small speaker without crowding the space above your head. If the shelf is above where you sit, check the sightline: at 10 inches deep and 18 inches above the desk, you will clip it with your head when you lean back.
See the desks if you are planning the pair together, the shelf depth and desk depth should not be the same number, or the shelf reads as a second desktop.
Why deeper is actively worse
Three reasons, and they compound.
Leverage. A floating shelf is a cantilever. The load sits away from the wall, and the further away it sits, the harder it pulls on the fixing. Doubling the depth roughly doubles the turning force at the wall for the same weight. A 12-inch shelf carrying books is working considerably harder than an 8-inch one carrying the same books.
Shadow. A deep shelf throws a shadow down the wall beneath it. On a dark wall nobody notices. On a pale wall a 12-inch shelf leaves a band of gray that makes the room feel lower than it is.
Clutter. A deep shelf gets a second row behind the first, and the second row is invisible, so it becomes storage for things you have forgotten you own.
Depth and thickness are not the same decision
Deeper shelves need thicker boards. A 6-inch shelf can be 1.25 inches thick and look right. A 12-inch shelf at 1.25 inches looks thin and starts to flex under a real load.
Rough pairing that holds up in practice: 6 inch deep with 1.25 to 1.5 inch thick, 8 to 10 inch with 1.75 to 2 inch, 12 inch with 2.5 inches or more.
This is proportion as much as engineering. A thick, deep shelf reads as a solid slab, which is the point of solid timber. A thin, deep shelf reads as a plank someone screwed to a wall.
Measure before you order, in this order
- Put the deepest object you plan to store on a table and measure it.
- Add one inch.
- Stand where you normally walk past and check nothing catches.
- If the shelf is above a work surface, check the depth against the counter, a shelf deeper than the counter below always looks like a mistake.
See the floating shelves, or send us the depth.
Common questions
How deep should a floating shelf be?
Most rooms want 6 to 10 inches. Depth follows the deepest thing you will put on it, not the size of the wall.
How deep should a kitchen shelf be?
11 to 12 inches. The number is set by dinner plates, which stack about 11 inches across, so 12 inches is the safe kitchen depth.
How deep should a bathroom shelf be?
6 to 8 inches. Bathrooms hold small items, and a deeper shelf in a small room reads heavy without holding more.
How deep should a shelf above a television be?
Above a television, 8 inches is usually enough and looks lighter than 10.
From the Rootelier range
Organic Decorative Wall Shelf and Curved Wall Shelf, or see all floating shelves. Every piece is made to order, so sizes can be adjusted to the room.