Bulbs, clips and strands for 150 ft, by bulb type
At 150 ft you are lighting the front and a side of the house, or a large two-story roofline with several gables. The counts include 10% extra for corners, gaps and a spare, and assume 25 ft strands. The number of bulbs sets the number of clips, because each bulb usually gets its own clip.
| Bulb type and spacing | Bulbs | Clips | 25 ft strands |
|---|---|---|---|
| Mini lights, 4 in apart | 495 | 495 | 7 |
| C6, 6 in apart | 330 | 330 | 7 |
| C7 or C9, 12 in apart | 165 | 165 | 7 |
| C9, 15 in apart | 132 | 132 | 7 |
Strands needed by strand length
Strand lengths vary by brand and bulb type, so check the box. These are the strands for 150 ft with no spare, with 10% spare (our recommendation) and with 20% spare for a roofline with many corners and peaks.
| Strand length | No spare | 10% spare | 20% spare |
|---|---|---|---|
| 17 ft strands | 9 | 10 | 11 |
| 25 ft strands | 6 | 7 | 8 |
| 33 ft strands | 5 | 5 | 6 |
| 50 ft strands | 3 | 4 | 4 |
Planning the 150 ft run
At 150 ft it is worth splitting the run into two circuits that start from different outdoor outlets, so a fault or a tripped GFCI only darkens half the house. Longer 50 ft strands cut the connections to 4.
Plug outdoor lights into a GFCI-protected outdoor outlet and use outdoor-rated cords and a timer. LED strands draw a fraction of the power of incandescent ones, which is why many more of them can be linked. For the tree, use the tree lights calculator, and the Christmas lights guide covers the whole house.
Want to change anything else? The calculator above is the full Outdoor Christmas Lights Calculator: edit any number and the results update instantly.
Tools & materials for this project
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Frequently asked questions
How many Christmas lights do I need for a 150 ft roofline?
With C7 or C9 bulbs 12 in apart and 10% extra for corners and a spare, a 150 ft roofline needs 165 bulbs, which is 7 strands of 25 ft. Mini lights 4 in apart need 495 bulbs along the same line.
How many light clips for 150 ft of roofline?
One clip per bulb: 165 clips for C9 bulbs 12 in apart, or 132 at 15 in spacing. Buy clips that match your gutter or shingles, and never staple through the wire.
How many strands of lights for 150 ft?
7 strands of 25 ft, including 10% extra. With 50 ft strands it is 4. Lights follow corners and gable peaks, so measure along the line the lights will take rather than the straight wall.
How many light strands can one outdoor outlet run?
A 15 A circuit should carry no more than 1,440 W of continuous load, and a 20 A circuit 1,920 W. Add up the watts printed on each box, and use the circuit load calculator if you are combining strands with other decorations.
Related sizes and guides
Related sizes
Estimates only. Results assume standard materials and simple shapes. Supplier products vary, and the final call on quantity, structure and safety is yours. Check your local code and your supplier's guidance before ordering.