Cool How Many Lights Needed For 6Ft Christmas Tree References. Kiplinger, the personal finance site, offers a wonderfully geeky formula to calculate a holiday power bill: Measure the height of your tree.
3'l branch / 3 spacing = 12 x 6 circumference = 6' of lighting per branch. For trees that are 7 feet tall, a good bulb count is 700 to 1,050 lights. Secure the lights to one of the bottom branches and work your way directly upwards from there, laying and crossing the string lights over various branches as you go to make sure the lights stay in place.
