Enter the power usage rate, run time, and electricity cost into the calculator to determine the grow light cost.

Grow Light Cost Formula

The following equation is used to calculate the Grow Light Cost.


  • Where GLC is the grow light cost per day ($)
  • EC is the electricity cost ($/kwh)
  • T is the average time of usage per day (hours)
  • P is the power usage of the light (kWh)

To calculate the cost of a grow light, multiply the average usage time per day by the power rating of the light, then multiply by the electricity cost.

What is the Cost to Run A Grow Light?

The cost to run a grow light depends on 3 factors:

  1. The cost of electricity. This is highly dependent on location and the source of electricity. For example, solar energy would be cheaper than that from the grid.
  2. The daily run time of the light. The longer the light runs, the more it will cost.
  3. The power usage per hour of the light. The higher the power usage the greater the cost.

How to Calculate Grow Light Cost?

Example Problem:

The following example outlines the steps and information needed to calculate Grow Light Cost.

First, determine the cost of electricity. In this example, the cost is $.125 /kWh.

Next, determine the daily run time. For this problem, the light runs for 24 hours a day.

Next, determine the power rating of the light. This grow light has a rating of .445 kWh.

Finally, calculate the grow light cost using the formula above:


GLC = .125*24*.445

GLC = $1.33 / day