Christmas Tree Size Calculator
What size tree should you buy? Tell us your ceiling height, the floor space where the tree will go, and how full you want it. We'll recommend the right height, base diameter, and check how it fits in your room.
Your room
Where the tree will go.
Your tree
Style preferences.
Your ideal Christmas tree
Perfect proportionTree height
6 ft
Rounded to nearest size sold by retailers
Base diameter
40"
medium shape
Floor footprint
42" × 42"
Includes clearance (49% of available space)
Proportion notes
Perfect proportion — the tree feels intentional in the space without crowding it.
About a medium tree
Medium-width trees are the standard shape — the 'Christmas tree' silhouette most people picture. Best for rooms with normal proportions and average ceiling heights.
Next steps
Now that you know your tree size, plan the rest:
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How the math works
Tree height:a tree should clear your ceiling by at least 12 inches for breathing room and topper clearance. We also subtract 9 inches if you're using a topper. So an 8-ft ceiling supports a tree up to ~6.5 ft tall with a topper, or 7 ft without — we round to the nearest standard height retailers actually sell.
Base diameter depends on tree shape. Industry standards:
- Slim: base diameter ≈ 40% of height
- Medium:≈ 55% of height (the standard "Christmas tree" silhouette)
- Full: ≈ 70% of height (wider, more dramatic)
Footprint: the tree itself is the base diameter, but you also need clearance around it. Corner placements need the least, center-of-room placements need the most because the tree is viewable from all sides.
Proportion check: we calculate what percentage of your available floor space the tree (with clearance) consumes. Under 25% is comfortable. 25–50% is the sweet spot. 50–75% is grand. Over 75% is tight — consider one size down.