Bedroom Sizes
Calculators for the measurements a bedroom comes down to: the bed that fits the room, the comforter on it, the nightstands beside it, the headboard behind it, the rug under it, the art above it, the curtains or blinds at the window and the fan and lights overhead. Setting up a nursery? Start with the checklist.

The bed
Start with the bed that fits the room, then find the comforter that covers the mattress, the nightstands that sit level with it, the headboard behind it and the rug that frames the bed.
On the walls
Size the art above the headboard, and set the height of a TV you watch from bed.
Mounting height by TV size
Windows
Size the curtain rod and how high to hang it, the curtain length and the panels to buy, or the blind or shade for the window.
Light and air
Work out how much light the room needs and the ceiling fan that suits it.
The nursery
Make a nursery checklist for your plans, from the first bed to diaper changes and feeding, with safe sleep notes and where things go.
Start with the bed
A bedroom is planned around its bed, and the bedding is the first size most people get wrong. The comforter size calculator takes your bed size and the depth of your mattress, pillow top included, and works out the comforter that covers the sides the way you like: just to the edge, a little past it or almost to the floor. Deep mattresses are where a standard size falls short, and the calculator shows when to size up.
Behind it, the headboard size calculator gives the width for your bed and how tall to go, from a low headboard to a tall one, with where to hang it on the wall and how high it can sit under a window.
Under the bed, a rug frames it. The rug size calculator sizes one for your bed and room, under the whole bed or under its lower two-thirds, with floor left at the walls.
Art above the bed, a TV across from it

Above the headboard, look for art about two-thirds to three-quarters as wide as the bed. The wall art size calculator turns your bed size into the width to shop for and checks it against standard frame and canvas sizes.
If you watch TV from bed, measure your eye height sitting up against the pillows. The TV mounting height calculator centers the screen at that height, and moves it up when a dresser sits under it.
Curtains at the window

In a bedroom, curtains that close fully matter as much as how they look. The curtain size calculator sizes the rod so the curtains clear the glass when open, sets its height and works out the panels for the fullness you want, from a standard look to sheers.
Lighting and a ceiling fan
A bedroom needs less general light than a kitchen, and a lamp where you read. The room lumens calculator turns the room's size into the lumens to plan for and the number of bulbs that add up to them.
For a ceiling fan, the room's floor area decides the blade span and the ceiling height decides the downrod. The ceiling fan size calculator works out both and checks that the blades stay clear of the floor and the walls.
How these tools work
Each calculator states the rule it uses and the assumptions behind it, right on the page under "How we calculate." The result is a starting point you can adjust to your room.
Everything runs in your browser: the numbers you type stay on your device. Use Copy link to save a result or send it to someone helping you shop.
From the blog

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11 Headboard Ideas, With the Sizes That Make Them Work
Eleven headboard ideas with the numbers behind them: the width for your bed, tall and low looks, panels on the wall, a bed under a window, and no headboard.Read the ideas
12 Nursery Ideas, With the Sizes and Safety Rules That Make Them Work
Twelve nursery ideas with the numbers behind them: a bare crib, room sharing, where the crib goes, cordless shades, a feeding corner and the safety basics.Read the ideas
12 Small Bedroom Ideas, With the Sizes That Make Them Fit
Twelve small bedroom ideas with the measurements behind them: the bed your room fits, narrow nightstands, wall lights, headboards, curtains, rugs and more.Read the ideas