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Calcimator

Grow Room Electricity Calculator

Estimate daily and monthly electricity costs for your indoor grow room lights, fans, and pumps.

Inputs

W
hrs
W
W
$/kWh

Results

Monthly Cost

$34.16

≈ 7 cups of coffee

Annual Cost

$409.92

≈ 7 tanks of gas

Daily Usage8.76 kWh
Monthly Usage262.8 kWh
How to Use This Calculator
  1. Enter the total wattage of all your grow lights (e.g., 400W HPS or 240W LED) and the hours they run per day.
  2. Enter fan wattage (total of all inline and oscillating fans, typically run 24/7) and pump wattage for hydro systems.
  3. Enter your electricity rate in $/kWh — find this on your utility bill.
  4. Review Monthly Cost and Annual Cost to understand the total operating expense of your grow room.
  5. Use the Daily kWh figure to compare different lighting setups or identify energy-saving opportunities.

How the result changes with Electricity Rate

Electricity RateMonthly CostAnnual Cost
0.11$28.65$343.80
0.36$93.56$1,122.72
0.65$171.61$2,059.32
0.9$236.78$2,841.36

What each input means

Light Wattage
Total wattage of all grow lights (e.g., 400W HPS or 240W LED).
Light Hours per Day
Hours lights are on per day (veg: 18, flower: 12).
Fan Wattage
Total wattage of inline and oscillating fans (run 24/7).
Pump Wattage
Water/air pump wattage if using hydroponics (0 for soil grows).
Electricity Rate
Your cost per kilowatt-hour from your utility bill.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Light Wattage = 400, Light Hours per Day = 18, Fan Wattage = 50, Pump Wattage = 15 = 5 input(s) provided
  2. Calculate Monthly Cost
    Monthly Cost
    34.16 = $34.16
  3. Calculate Daily Usage
    Daily Usage
    8.76 = 8.76
  4. Calculate Monthly Usage
    Monthly Usage
    262.8 = 262.8

Engine last updated . Checked against 1 independently-derived test — how we verify calculators.

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