Christmas Tree Size Calculator
Find the tallest full, slim or pencil Christmas tree that fits under your ceiling and in the spot you have for it, and how wide it is.
A tree has to clear the ceiling with room for a topper, and it has to fit the floor with room for the skirt. Width is the one that catches people out: a full 7-foot tree is about 4½ feet wide.
Tree shape you want
Full trees are the most common; slim and pencil trees fit smaller spaces.
Your ceiling
Measure from the floor to the ceiling where the tree will stand.
Width of the spot
How wide the spot is, wall to furniture or between pieces.
Tree to look for
A 7 ft full tree
About 4½ ft wide, and the tallest for your 8 ft ceiling
Leaves a foot for a topper under the ceiling and 6 inches all round for the skirt and presents. Artificial tree heights include the stand; a real tree on a lot is measured without one, so pick one a little shorter.
💡About this calculator▼
A Christmas tree has two limits. It has to clear the ceiling with room for a star or angel on top, and it has to fit the floor with room for the skirt and presents. The ceiling is easy to judge; the width is what catches people out, because a full 7-foot tree is about 4½ feet wide.
Start with the shape you want, full, slim or pencil, then enter your ceiling height and the width of the spot. You get the tallest tree of that shape that fits both, and about how wide it is.
If the spot cuts it short, the calculator says which narrower shape would let you go taller, often a slim tree at full height where a full tree would have to be a foot or two shorter.
The ceiling limit. Tree makers measure artificial trees from the bottom of the stand to the tip, and their rule is to subtract 12 inches from the ceiling to leave room for a topper. Trees are sold in half-foot sizes, so this rounds down: an 8-foot ceiling allows a 7-foot tree.
The width limit. The same makers subtract 12 inches from the floor space, about 6 inches all round for the tree skirt and presents. A 6-foot-wide spot allows a tree up to 5 feet wide.
How wide each shape is. A full tree is about two-thirds as wide as it is tall, a slim tree about half and a pencil tree about a third, going by one maker's 7½-foot tree in all three shapes (59, 48 and 32 inches across).
The answer. The tallest tree of your shape is whichever limit it reaches first. When the width limit wins, the calculator checks the narrower shapes and suggests the one that reaches your ceiling height, or failing that, the one that gets tallest.
Worked example. A full tree, an 8-foot ceiling and a spot 5 feet wide: the ceiling allows 7 feet, but the spot allows only 4 feet of width, and a full 7-foot tree is about 4⅔ feet wide. So a full tree tops out at 6 feet (4 feet wide), and a slim 7-foot tree, about 3½ feet wide, would fit instead.
📐How it's calculated▼
Ceiling limit = ceiling − 1 ft, rounded down to the half foot. Width limit = spot width − 1 ft.
Tallest tree of your shape = the smaller of the ceiling limit and width limit ÷ shape fraction, rounded down to the half foot. Shape fraction: full 2/3, slim 1/2, pencil 1/3. Tree width = height × fraction.
Full, 8 ft ceiling, 6 ft spot: a 7 ft full tree, about 4½ ft wide. Full, 8 ft ceiling, 5 ft spot: a 6 ft full tree; for 7 ft, choose slim. Pencil, 8 ft ceiling, 3 ft spot: a 6 ft pencil tree, about 2 ft wide.
📎Source:Balsam Hill — Artificial Christmas Tree Size Guide (ceiling and floor-space allowances)
🔍Finding your inputs▼
Tree shape you want: Full is the classic wide cone and the most common. Slim trees are about three-quarters as wide as a full tree of the same height, and pencil trees about half, for tight corners and small rooms.
Your ceiling: Measure from the floor to the ceiling where the tree will stand. Sloped or vaulted ceilings vary across the room, so measure at the spot itself.
Width of the spot: How wide the spot is, from wall to furniture or between pieces of furniture. A foot of it is kept for the tree skirt and presents.
⚠️Special situations▼
My tree is a real one from a lot
Lot trees are measured by the tree alone, and the stand raises it, so pick one a little shorter than the height shown. Artificial trees are measured with their stand.
I won’t use a topper
Then you can go about 6 inches taller: tree makers subtract 6 inches from the ceiling without a topper instead of 12. On an 8-foot ceiling that is still a 7-foot tree in the usual half-foot sizes, unless you find a 7½-foot one and measure carefully.
The tree goes in a corner
Measure the width along the shorter wall; a round tree needs that much in both directions. Flatback trees, made to sit against a wall, take about half the floor space of a full tree.
❓Common questions▼
What size Christmas tree for an 8 ft ceiling?
A 7-foot tree. The rule is to subtract a foot from the ceiling so there is room for a topper. A full 7-foot tree is about 4½ feet wide and needs a spot about 5½ feet wide; a slim one about 4½ feet.
What size Christmas tree for a 9 ft ceiling?
An 8-foot tree, or a 7½-foot one if you want more room above. A full 8-foot tree is about 5½ feet wide and needs a spot about 6½ feet wide.
What size Christmas tree for a 10 ft ceiling?
A 9-foot tree. A full 9-foot tree is about 6 feet wide and needs a spot about 7 feet wide; a slim one is about 4½ feet wide.
How wide is a Christmas tree?
A full tree is about two-thirds as wide as it is tall, a slim tree about half and a pencil tree about a third. A 7½-foot tree in one maker's range is 59 inches across full, 48 slim and 32 as a pencil tree.
How much room should I leave around a Christmas tree?
About 6 inches all round for the skirt and presents, which is why the calculator keeps a foot of your spot's width. Leave more near doorways and walkways, and keep the tree away from fireplaces, radiators and candles.
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