How this calculator works
Subtract the height of the stand, the topper and a small gap from the ceiling height to find the tallest tree that fits. Trees are sold in standard heights, so pick the largest that is not taller than that. A full tree is about 60% as wide as it is tall, and needs a foot or so of clear floor on every side.
Worked example: with an 8 ft ceiling, a 3 inch stand, an 8 inch topper and a 1 inch gap, the tallest tree is 7.0 ft (84 inches), so a 7 ft tree. It is about 50 inches wide at the base and needs 6.2 ft of clear floor. With a 9 ft ceiling the tree can be 8 ft.
Tree height by ceiling height (3 in stand, 8 in topper, 1 in gap)
The largest standard size, with its approximate width.
| Ceiling | Tallest tree | Standard size | Width at the base |
|---|---|---|---|
| 7 ft | 6.0 ft | 6 ft | 43 in |
| 7.5 ft | 6.5 ft | 6.5 ft | 47 in |
| 8 ft | 7.0 ft | 7 ft | 50 in |
| 9 ft | 8.0 ft | 8 ft | 58 in |
| 10 ft | 9.0 ft | 9 ft | 65 in |
| 12 ft | 11.0 ft | 10 ft | 72 in |
Tips before you buy
- Measure first and buy later. A tree that touches the ceiling looks cramped, and the topper has to fit.
- Bring the tree in a day before you decorate, so that the branches can drop and open, and cut an inch off the trunk base for a real tree to help it take up water.
- A real tree needs water every day. Fill the stand to the top and check it often, because a dry tree is a fire risk.
- Allow for the width of the room, not just the height: the base of a 7.5 ft tree is about 3½ feet across.
- If you are short of space, a slim or pencil tree gives you the height with less width.
Tools & materials for this project
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Frequently asked questions
What size Christmas tree for an 8 foot ceiling?
A 7 ft tree, after allowing for a 3 inch stand, an 8 inch topper and a 1 inch gap under the ceiling: about a foot off the ceiling height. Choose a shorter topper to go a size up.
How tall should a Christmas tree be for a 9 foot ceiling?
A 8 ft tree is the largest that fits with the same stand, topper and gap: again about a foot off the ceiling height.
How wide is a 7.5 foot Christmas tree?
A full tree is about 60% as wide as it is tall, so a 7.5 ft tree is about 54 inches (4.5 ft) across at the base. Slim trees are narrower.
How many lights do I need for a Christmas tree?
About 100 per foot of tree for a classic look, so 700 lights for a 7 ft tree, and 150 per foot for a dense one.
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Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.