When trying to calculate how many lights are needed for trees, there are a few industry standards, as well as considerations that must be taken.
Quick Light Calculation Q/A
What is the best method for wrapping trees?
How many lights do I need per tree?
What size lights are best? Mini Lights.
There is no exact calculation to determine how many lights are required to light outdoor trees. Slender and deciduous trees will require the least amount of lights for desired affect. Evergreen trees including Spruce, Pines and Firs that retain most of their foliage in the winter may require up to 25% more lights than the recommended count.
Recommended Number of Lights for Outdoor Trees
Recommended Number of Lights for Christmas Trees
Rule of Thumb: Christmas trees
For medium lighting, figure 100 mini lights per vertical foot of the tree
For heavy lighting, figure 200 mini lights per vertical foot
Factors in Bulb Spacing and String Length
String length is a consideration when calculating how many lights are needed. 100 light count strings can come with various spacing between bulbs, resulting in string lengths that can differ by 15' or more.
Indoor Christmas trees: Light counts are standard with the chart below, following the rule of thumb for 100 lights per vertical foot
Most popular: 4" bulb spacing to allow for maximum lighting with minimal wire
If wrapping branches: 6" or 8" spacing is recommended to allow space for wire to wrap tightly around each branch
Evergreen trees are thick, needing additional string length to ensure complete coverage. 6" bulb spacing is ideal. Consider using C7 and C9 bulbs.
Deciduous trees shed leaves, requiring fewer lights if simply draping and more if wrapping trunks and branches. 8" spacing is ideal.
Trunks and branches require higher light counts. Learn more through our dedicated resource page for Wrapping Outdoor Trees with Lights. For lots of lights, 4-5 light strings should cover trunks and main branches. Many trunks can be wrapped with 1-2.
Bushes and hedges - light counts remain standard, however many people choose to use net lights for quick and even coverage. When using light strings, choose random light patterns as opposed to uniform for best effect.
Popular Lights for Trees
The type of light string chosen makes a difference in light count. The most popular bulb sizes for trees are mini lights, 5mm wide angle LED bulbs, and C7 bulbs.
Mini lights: the most popular bulb in Christmas tree lights for indoor and outdoor use5mm LED lights: the preferred LED bulb size for indoor Christmas trees. Less bulbs are required per foot since the light in a wide angle LED light is much brighter than an incandescent mini light. Over 3,000 5mm LED bulbs can be connected together - approximately 48 sets of lights.
Standard grade - 210 watts can be connected, (typically 600 bulbs)
Premium grade - 210 watts can be connected (typically 600 bulbs), includes lamp lock to ensure bulb stays secure in the socket
Commercial grade - 420 watts can be connected (typically 1,000 bulbs)
C7 bulbs: a popular bulb size due to its retro appearance. Larger in size and light output, far less C7 bulbs are required for tree lighting than mini lights
C9 bulbs: intended for large and overly dense or tall outdoor trees
C6 Green Strawberry Lights Wrapped in Trees
Light Calculations for Power
Every Christmas lighting project requires light calculations for power. Lights will burn brighter and last longer when the proper calculations are used to determine how many lights can be plugged together. The UL standard for how many lights can be connected has recently changed, allowing for up to 210 watts to be plugged together on a standard 22 gauge wire, and 410 watts on a commercial grade 20 gauge wire. C7 bulbs vary greatly depending in wire gauge used, which can be as thick as 18 gauge, allowing for up to 100 C7 bulbs to be connected.
Lights on Outdoor Trees
To best determine how many Christmas lights you need, we recommend lighting counts based on:Before the decorating begins, plug up each string to test it. It is a lot easier to correct any issues before the lights are on the tree.
Indoor Christmas trees
Lights for outdoor Christmas trees
Bushes and hedges
Wrapping trunks and branches
Hanging Christmas lights on rooflines and down walkways
Christmas trees: When stringing lights, start from the top of the tree and work your way to the bottom. The female end of the plug can be connected to the tree topper.
Christmas trees: Run the light strings along the inside of the tree branches to give the tree more depth.
Outdoor trees: Start at the base of the tree, work your way up the trunk and branches, and back down.
Personal preference is the ultimate deciding factor, so while these are recommended counts, you should be safe increasing or decreasing the bulb count to your own tastes.
Common Light Types for Trees
Types of Tree Lights (clear or color)
Use: tree trunks and branches
Clear, color and twinkle
Connect up to 500 bulbs
Wide Angle 5MM LEDs
Use: tree trunks, branches, bushes
Bright colors, whites, twinkle
Connect over 3,000 bulbs!
M5 LED Mini Lights
Use: tree trunks, branches and bushes
Bright bold colors, soft white light
Connect over 3,000 bulbs!
LED Light Tubes
Hang from tree limbs
Resembles falling snow or meteors
Unique bulbs with C7/C9 bases
C6 Stawberry LED Lights
Use: wrapping tree canopy
Also great in hedges and shrubs
Connect over 3,000 bulbs!
G20 LED Lights
Round 20mm globe lights
Use: trees, dense greenery
Connect many LEDs!
Christmas Lights Unlimited specializes in Large Holiday Light Displays across the United States.
Christmas Lights Unlimited will not install materials provided by clients, unless approved. All products supplied by Christmas Lights Unlimited are made to the highest quality. Products selected by Christmas Lights Unlimited must meet the follow (1) Extension Cords are marine grade with waterproof twist connectors, (2) String Light Strands are solid molded with waterproof coaxial connectors, (3) All products manufactured exceed the Canada Requirements (exceeding USA Requirements), (4) Timers designed to handled 15AMPS / Peak 1,875 WATTS / Tungsten 1,875 WATTS to support a Constant 1,875 WATTS and (5) All electrical wiring are heavy duty commercial grade wire (AWG) with thicker electrical safety coatings.
Our Christmas Light Strands cannot be purchased in Big Box Stores.
Clients must meet strict electrical requirements with dedicated outlets for safety and proper installation for Christmas Lights Unlimited Displays.