House Decorated with Christmas Lights

To best determine how many Christmas lights you need, we recommend lighting counts based on:

• Indoor Christmas trees
• Lights for outdoor Christmas trees
• Bushes and hedges
• Wrapping trunks and branches
• Hanging Christmas lights on rooflines and down walkways
• Power Needs

How Many Christmas Lights for Trees

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.

Rule of Thumb

• For medium lighting, figure 100 mini lights per vertical foot of the tree
• For heavy lighting, figure 200 mini lights per vertical foot

Recommended Number of Lights for Christmas Trees

Recommended Number of Lights for Outdoor Trees

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.

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
• Outdoor trees
  • Evergreen trees are thick, needing additional string length to ensure complete coverage. 6" bulb spacing is ideal
  • Deciduous trees shed leaves, requiring fewer lights if simply draping and more if wrapping trunks and branches
  • Trunks and branches require higher light counts. Learn more through our dedicated resource page for Wrapping Outdoor Trees with Lights
  • 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 use
  • 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)
• 5mm 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.
• 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

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.

For additional detail, read our informational page on Power Consumption for Outdoor Trees

LED Lights on Outdoor Trees

Additional Tips

• 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.
• 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.
• Run the light strings along the inside of the tree branches to give the tree more depth.
• 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.