Your ceiling, minus three things
Most people buy a tree one size too tall. The tag on a tree lot measures the tree alone. At home the tree sits on a stand, wears a topper, and needs a gap under the ceiling so you have room to place that topper without bending the tip. All three come out of your ceiling height before you know what to buy.
Press Load sample and the calculator walks through a standard 8 ft living room with a cut tree:
76 inches is 6 ft 4 in. Tree lots sort stock by the whole foot, so the answer is a 6 ft tree. Switch the same room to Artificial and the answer climbs to 6.5 ft, because a fake tree's listed height already counts its base, so the 4 in stand lift drops out of the math.
Christmas tree size by ceiling height
The table uses the calculator's defaults: a 10 in topper, a 6 in gap, a 4 in stand lift on cut trees, and a full shape. Change any of those above and your row moves.
| Ceiling | Cut tree to buy | Artificial size | Branch spread (cut, full) |
|---|---|---|---|
| 7.5 ft | 5 ft | 6 ft | 39 in |
| 8 ft | 6 ft | 6.5 ft | 47 in |
| 9 ft | 7 ft | 7.5 ft | 55 in |
| 10 ft | 8 ft | 8 ft | 62 in |
| 12 ft | 10 ft | 10 ft | 78 in |
Artificial sizes follow common store sizes: 6, 6.5, 7, 7.5, 8, 9, 10 and 12 ft.
Look at the 10 ft row. The artificial column stalls at 8 ft even with 104 in free, because the next stock size up is 9 ft, or 108 in. The calculator shows the leftover space as spare above the topper in the drawing. A taller topper or a tree-top bow fills a gap like this better than a tree you would have to cut down.
Width decides more than height
A low ceiling is easy to see. A tight floor is not, and a tree too wide for its corner ends up shoved against the curtains with its back branches crushed flat. Three 7 ft trees from the same lot:
- Pencil: 29 in across. Fits beside a fireplace or in a hallway nook.
- Full: 55 in across. The shape most people picture.
- Extra full: 67 in across, more than 5.5 ft of floor before anyone sets a gift down.
Put a number in Floor width available and the calculator warns you when the branches will not clear, then names the slimmer shape or shorter height to fit. The floor space figure adds 12 in on top of the branch spread, a 6 in ring around the tree for presents and for vacuuming needles.
How many lights a Christmas tree needs
The old rule says 100 mini lights per foot of tree. The rule holds for a full 7 ft tree and drifts everywhere else, because lights cover surface, and surface grows with both height and width. A pencil tree has about half the branches of a full one at the same height. A 10 ft tree has twice the surface of a 7 ft one, not 43% more.
The calculator treats the tree as a cone and counts bulbs per square foot of its outside:
For a full 7 ft tree, Balanced gives 700 bulbs, so the 100-per-foot rule lands right. Light touch drops to 480, the look of a tree with branches showing between the lights. Loaded climbs to 1,060, the dense glow you see in hotel lobbies. A 7 ft pencil tree needs 370.
Before you chain sets together, read the tag near the plug. Older incandescent mini sets often allow only three sets end to end. LED sets draw far less current and usually allow many more. When your total runs past the limit, run two or three separate leads up the trunk and plug them into a power strip at the base.
Ornaments
Ornament counts use the same surface figure, at 2 per square foot for Balanced. A full 7 ft tree takes about 105. The calculator splits the total into a rough mix: 15% large, 45% medium, 40% small, or 16, 47 and 42 for that tree. Hang the large ones low and deep toward the trunk, where they fill holes, and keep the small ones on the top third, where branches get short.
Garland
Garland wraps the tree as a spiral, one turn every 12 in of height on Balanced, every 18 in on Light touch, and every 9 in on Loaded. The length of a spiral around a cone works out like this:
The extra 10% covers the droop between branches. A full 7 ft tree needs about 56 ft, or seven 9 ft lengths. Swagged garland, hung in loops from branch tip to branch tip instead of wrapped, eats more, so buy one extra length for that style.
Tree skirt
The skirt suggestion rounds down to the nearest stock size under your branch spread: 30, 36, 42, 48, 52, 56, 60 or 72 in. A skirt wider than the bottom branches sticks out past them and catches feet. A full 7 ft tree spreads 55 in, so the pick is a 52 in skirt.
Before you tie a real tree to the roof
- Measure at the lot. Stand the tree up and run a tape from the cut end to the tip of the top shoot. Tags round, and a "6 ft" tree often stretches past 6.5 ft.
- Check the trunk against your stand. A trunk too thick for the bowl means shaving bark at home, and bark is where the tree takes in water.
- Ask for a fresh cut, then get the tree into water within a few hours. A dry cut end seals over with sap and the tree stops drinking.
- Size the stand's water bowl. Plan on about 1 quart of water per inch of trunk diameter. A fresh tree drinks the most in the first few days, so check the level every morning.
- Measure the door. A netted 7 ft tree goes through a standard doorway. An unnetted extra full one might not.
Where the numbers fall short
- Vaulted and sloped ceilings. Measure straight up from the spot where the trunk will stand, not at the peak. A tree under the low end of a slope needs the low number.
- Ceiling fans and pendant lights. Use the distance to the lowest point of the fixture if the tree sits under one.
- Corner placement. The light and ornament counts cover the whole cone. A tree tucked into a corner hides a quarter to a third of its surface, so you can trim the back if you want to save bulbs.
- Big bulbs. Counts assume mini lights. C7 and C9 bulbs sit farther apart on the wire, so these numbers run high for them.
- Every tree is a little different. The four shapes are averages. Wild lot trees with long lower limbs spread wider than any of them, which is why the tape at the lot beats any calculator.