Ask a customer why their indoor tree looks underdressed and you will hear "the lights were too few." More often it was the wrap. The tree is a cone, the wire is a line, and if you start at the base and pull up through the branches, you end up with a glowing skeleton and a dark middle. I have untangled enough of these to stop apologizing: the tree was never underdressed, the string was placed against the geometry.
The math: how much string a tree actually eats
Measure once and the number does the arguing for you. Take the circumference of the base, add the height, multiply by roughly four and a half. That is the wire a single full pass around a conical tree needs, because each wrap starts wider and ends higher. A tree with a 42-inch base and a 66-inch height needs about 20 feet per pass, and people quote 6-foot trees as if the wire should be 6 feet long. It is not.
Standard indoor strings come in 10, 15 or 20-foot runs, so the base circumference decides everything. A 42-inch base wants two full 20-foot passes to look finished; a 30-inch tabletop tree swallows one pass and still leaves the top bare. When I quote coverage for a shop display I run one number per tree: base diameter in inches, plus 30, equals the feet of string per set. A 40-inch base wants a 70-foot total, two sets. A 24-inch base wants one 50-foot set and nothing else. The math does not flatter, so it is useful.
Wrap from the top, not the floor
Everyone starts at the bottom because that is where the socket lives. Do it anyway, but start the first wrap at the top third. Take the lead wire to the peak, run it down and around to the back, and come forward through a branch. The second wrap starts where the first ended, and you keep the spacing between wraps to 4 to 6 inches as you descend. Two things to hold: never let a wrap cross over a previous wrap at the same height, and always push the wire into the branch tips so the light comes out of the foliage, not out of a clean gap. The tree is a cone. A cone shows its gaps on the inside, which is exactly where a bottom-up wrap leaves them.
I learned the crossing rule the expensive way on a mall window tree. Twelve strands, three of them crossed at the mid-tier, and the crossed section read as a bright band while the rest of the tree read as shadow. The customer photographed the band. The tree was fine. The order was not.
Plug order: one live set at a time
The other reason indoor trees look dim is not the chip, it is the outlet. Three 100-LED strings on one adapter or one short extension, each set running around 20 watts or less on modern LED, and the voltage sags at the far end of each run. The fix is boring: one set per outlet, or a 10-amp branch that is not also carrying a space heater, and keep the daisy-chain under two sets unless the manufacturer prints more. When a store display dims by week two, I check the outlet before I check the LED, and nine times out of ten the socket is the story.
For the tree itself, a 300 LED Christmas Tree String Light set is the one I keep on the shelf: dense enough for a 6-foot tree in one pass and half a wrap of the top. For a display that needs a second layer on a tabletop or a shop front, a 200 LED Cool White String Light run works as the inner accent. And when the same tree moves outside for the week before the shop close, the weatherproof 500 LED Outdoor Christmas Chain Light is the one that should have been bought first, not after the first snow.
So the next time a tree looks bare, do not buy another strand before you have run the math. Base plus height, times four and a half, is the wire that tree owes you, and the wrap that starts at the top is the one that fills the middle. The LED was never the argument.
Frequently asked
How many christmas string lights do I need for a 6-foot tree? Roughly 40 to 70 feet of wire. Run the base circumference plus the height, multiply by 4.5, and buy enough string to cover it in clean passes of 15 to 20 feet each.
Where do I start wrapping christmas string lights on a tree? At the top. Take the lead wire to the peak, come down and around, and keep the spacing between wraps at 4 to 6 inches. Starting at the base is why the middle of the tree reads dark.
Why is my indoor tree dim with led christmas lights even though every bulb lights? Usually the outlet and the daisy-chain, not the chip. Two or more sets on one adapter or one short extension sags the voltage at the far end of each run. One set per outlet fixes most of it.