Every December, the same scene plays out: you're halfway around the tree, the string runs out, and the store is sold out of the exact set you started with. Buying the right amount of lights the first time is easier than it sounds — there's a simple formula for trees, and reliable numbers for windows, garlands, and staircases. And here's the quiet secret experienced decorators know: late summer and early fall are the smartest time to stock up, before the seasonal rush cleans out the shelves.
The Tree Formula: 100 Lights Per Foot (and When to Break the Rule)
The classic rule of thumb is 100 mini lights per vertical foot of tree. So:
- 4-foot tree: 400 lights (~130 ft of string)
- 6-foot tree: 600 lights (~200 ft)
- 7-foot tree: 700 lights (~230 ft)
- 9-foot tree: 900+ lights
That's a good-looking, evenly lit tree. Want that glowing, magazine-cover density? Go 150–200 per foot. Prefer a subtle, minimalist look with visible ornaments? You can drop to 50–75 per foot. Two more adjustments: fat trees need more — a full-bodied 7-footer can swallow 30% more lights than a slim "pencil" tree of the same height — and if you wrap deep into the branches (the pro technique, wrapping each major limb from trunk to tip and back) budget roughly double the surface-wrap amount.
Windows: Curtain Lights Beat String Lights
You can outline a window with string lights and tape, but curtain lights — vertical strands hanging from one horizontal wire — give you that full waterfall-of-light look in a fraction of the time. One curtain covers a standard window; a wide set covers sliding doors or an entire wall behind the tree. A set like the 300 LED warm white window curtain light spans about 9.8 × 9.8 feet with eight lighting modes, which handles most living room windows with drape to spare. For measuring: width of the window in feet × height in feet gives you the coverage area to match against the set's dimensions — don't forget you can let extra length pool on the sill for a soft glow.
Garlands, Mantels, and Staircases
- Mantel garland: a 6-foot garland looks right with 100–150 lights — one 33-foot fairy light string woven through does it nicely.
- Staircase railing: measure the railing and multiply by 1.5 to account for spiraling. A 10-foot banister needs about 15 feet of garland and 150–200 lights.
- Wreaths: 50–100 lights for a 24-inch wreath; battery-operated strings are the move here since wreaths rarely hang near an outlet.
For these wrap-and-weave jobs, thin-wire fairy lights are far easier to work with than traditional mini lights — the copper wire bends around branches and banisters and disappears when lit. The 99-foot 300 LED copper wire string lights with remote cover a mantel, a wreath, and a staircase from a single battery box — no outlet hunting behind the furniture.
Indoor vs. Outdoor: Check the Label Twice
Every string is rated indoor-only or indoor/outdoor. Outdoor-rated lights have sealed sockets and weatherproof wiring; indoor-only strings will fail (or trip breakers) in rain and snow. If there's any chance a string ends up on the porch or a shrub, buy outdoor-rated — it works fine inside too, and you keep your options open. We keep both types, plus battery, plug-in, and solar options, in the string lights and fairy lights collection — and if you're weighing power sources, our battery vs. plug-in vs. solar guide breaks down which fits each spot in the house.
Why Smart Decorators Buy in August and September
Three practical reasons to shop early:
- Selection: popular lengths and warm-white tones sell out first — by early December you're choosing from whatever's left.
- Testing time: buying early means you can plug in every string, check for dead sections, and swap or return calmly instead of at 9 p.m. on December 20th.
- Matching: if you need to add a string next year, buying extra from the same batch now beats hunting for a discontinued model later. The standard advice: buy 10–15% more than your calculation says. Leftover lights always find a job — a doorway, a bookshelf, a kid's headboard.
Your Quick Shopping Checklist
- Tree height × 100 lights (×2 for branch wrapping, +30% for a full tree)
- One curtain light set per major window
- 33 ft of fairy lights per 6-ft garland or wreath cluster
- Railing length × 1.5 for staircases
- Add 10–15% spare, and confirm outdoor rating for anything outside
Run the numbers once, buy once, and December becomes the fun part — decorating instead of re-shopping.
Beat the rush: browse the Holiday & Seasonal Decorations collection for curtain lights, fairy strings, and festive accents — stocked now, before the December scramble.