February 15, 2021
Required Lumens
Use this calculator to figure out how many lights to use in your grow room.
* To use this calculator, you must know the lumen rating of the lights you plan to use.
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Frequently Asked Questions
Why should I use this calculator?
Time to buy marijuana grow lights? Looking to maximize yield? You will need to calculate the lumen light needed to grow your own cannabis and get the best yield. This online calculator determines lumen needs based on the square footage of your grow space.
For this lumen estimation calculator, you will need the width and length of your room, and the number of lumens your specific marijuana grow light emits. This is usually found on the package. Although standard lights produce a small number of lumens, marijuana grow lights emit thousands of lumens.
Before you use this lighting calculator, pick a few different marijuana grow lights that you are thinking of buying. Write down how many lumens each light emits. Then use this calculator to decide on the best light choice for your grow space!
Sign up for the Cannabis Growing Pro Certificate Program to learn more about using lights to increase yield.
What are lumens?
Lumens are a measurement of visible light. In the most basic terms, lumens equal brightness. The number of lumens indicates how much light is produced by the bulb. Because of this, lumens and cannabis crop yield are related. The lumens rating affects the yield of your cannabis garden.
Sign up for the Cannabis Growing Pro Certificate Program to learn more about lighting in indoor marijuana grow rooms.
How many lumens do I need to grow marijuana in my house?
Use this online lumen estimation calculator to know how many lumens you need based on the square footage of your grow room. Put in the length and width of your grow space to calculate the lumens needed to grow your own cannabis in your space.
If you want to take it a step further, enter how many lumens your grow light emits. The grow light calculator will tell you how many lights you need for your indoor grow space.
Sign up for the Marijuana 101 Certificate Program to learn how to start growing marijuana indoors.
Will this lighting calculator help me with growing weed with LED lights?
This lighting calculator will help you with growing weed with LED lights! After you calculate the square footage of your grow room, enter the lumens of your LED lights to find the best lights to use for your cannabis grow room!
Sign up for the Marijuana 101 Certificate Program to learn how to use LED lights in indoor cannabis gardens.
What should be the light intensity for marijuana?
Lumens are a good measurement of light intensity for cannabis. The optimal light intensity for weed in commercial cannabis facilities is 7,000 to 10,000 lumens. A mid-range light intensity for pot is 5,000 lumens. At minimum, your marijuana grow room should have a light intensity for marijuana of at least 3,000 lumens.
Sign up for the Cannabis Growing Pro Certificate Program to learn more about marijuana grow room lighting.
How do I calculate the light required for growing cannabis?
Calculating the lumens needed to grow your own cannabis is one of the best questions to ask when you are planning to grow cannabis indoors. This is because light is directly related to yield. Without good light you will not have a good yield.
The best method to calculate grow light coverage is to determine what size space you’ll be growing in. Make sure the grow lights you’re considering will thoroughly cover that space with sufficient light. Having enough lumens is a part of making sure you have enough light in your room, but there are also other factors to consider including watts, kelvins, PAR watts, and PPFD.
Learn how much light you need to grow marijuana and more in the Cannabis Growing Pro Certificate Program.
Aside from lumens, are there other factors I should be considering in marijuana grow lights?
Yes! Lumens and cannabis yields are connected, but there are also other considerations when it comes to lights. Let’s break it down:
- Watts indicate how much electricity it will take to run the bulb. It is a good indicator of how much it will cost to run your grow lights. The amount of light produced by each watt can be very different depending on the type of light and how it was made.
- Kelvin indicates the color(s) of light that are produced by the bulb. Marijuana plants only need certain colors of light.
- Lumens indicate how much light is produced by the bulb. Because of this, the lumens rating is the parameter that most affects the yield of your cannabis garden.
- PAR watts indicate how much light energy is available to the plants for photosynthesis, taking the light color into consideration.
- PPFD indicates how much usable light gets to a specific location in your garden. A reputable lighting company will publish multiple values, including the distance from light source (vertical and horizontal), the number of measurements included in the average, and the min/max ratio.
In addition to lumens, your final lighting decision should account for the cost of the lights, the amount of electricity they will use, how well the light is distributed through your grow room (PPFD), and the amount of heat they will generate (which can affect fan and air conditioning costs).
Sign up for the Cannabis Growing Pro Certificate Program to learn more about lighting parameters and how they affect marijuana grow room lighting requirements!
How should I use the lumen estimation calculator?
The optimal number of lumens required for a successful marijuana grow room is based on the grow room size. Enter the length and width of your grow room to find out how many lumens you need in the room. Then, enter the number of lumens in the lights you’re planning to use to find out how many you need to install. Pay attention to the distance between your cannabis plants and the lights to ensure that they receive all available lumens.
Sign up for the Cannabis Growing Pro Certificate Program to learn more about lights in marijuana grow rooms.
I am getting a really high number of lights for my small space, is your calculator broken?
First, check to see that you are using marijuana grow lights in the grow light calculator! Regular (non-marijuana) grow lights usually emit hundreds of lumens. Marijuana grow lights emit tens of thousands of lumens!
Learn more about how lumen requirements are calculated in the Cannabis Growing Pro Certificate Program.
How many lumens does a typical grow light have?
The number of lumens produced by a cannabis grow light depends on the type of bulb, its wattage, and the specific light. Most cannabis grow lights produce at least 100 lumens per watt. Many produce more than 400 lumens per watt. Check the manufacturer specifications to learn how many lumens are produced by a specific light.
You can learn more about lighting choices in the Cannabis Growing Pro Certificate Program.
How does the calculator work?
The calculator uses user-entered data and simple arithmetic to calculate the required lumens and number of lights.
To learn more about how lumen requirements are calculated, sign up for the Cannabis Growing Pro Certificate Program.
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