Our grow room CO2 calculator makes figuring out the ideal flow rate easy. Many growers trying to introduce additional carbon dioxide ask, “How much CO2 do I need for my grow room?”
To use this CO2 Calculator, simply input the dimensions of your room. Our tool makes a few assumptions:
- The ambient CO2 level is around 300ppm
- The target CO2 level is around 1500ppm
- You will add CO2 for 15 minutes every hour
After you put in your dimensions, you’ll see your calculated CO2 flow rate in green. You can choose between the imperial or metric system.
Grow Room CO2 Flow Calculator
Room Dimensions (feet) Room Dimensions (meters)
Room Size
CO2 Level
Ambient CO2 Level {{ambientco2}} ppm
Target CO2 Level {{targetco2}} ppm
On {{cycleon}} minutes per hour
CO2 Flow Rate
{{scfperhour}} feet3 per hour* {{scmperhour}} meters3 per hour*
Using CO2 in your grow room or tent
Carbon dioxide (CO2) is one of the most important elements your plants need. They take in CO2 from the air via small pores in their leaves called stomata. They then use it as a building block to grow and bloom.
In natural conditions, CO2 levels range between 360-395 PPM. If you don’t keep CO2 levels topped up (either by ventilating with fresh air or supplementing with a CO2 cylinder or burner) your plants will run out of food, photosynthesis will slow, and plant growth will be lackluster.
If this happens you can expect stretched, leggy growth and airy, unimpressive flowers.
How to add CO2 to your grow room or tent
There are a few ways you can go about increasing CO2 in your grow. These include:
Which one of these is best for you will depend on the size of your grow, whether you are in a tent or room, and budget.
CO2 burners are awesome, but they take up a fair amount of space. Because of this, they work best in grow rooms. On the other hand, CO2 tanks can be placed outside the tent, with tubing running around the inside of the tent. In very small grows, a natural CO2 bag might be best, as your CO2 needs are lower.
Controlling CO2 in the grow environment
Adding CO2 to your grow is one thing, but you can't just turn it on and let it run. You need a way to control the flow rate so that your plants get ample CO2, without overdoing it.
CO2 controllers allow you to set your intervals for releasing CO2, and get that ideal flow rate you found with our grow room CO2 calculator.
Should every grower use CO2 in their grow?
CO2 supplementation can lead to seriously explosive growth, but it isn't right for every grow. You need to find out which factor is limiting your grow - light or CO2.
If you are using a very strong light, chances are you can benefit from CO2. But, if you don't have a really strong light for your grow, you might not benefit from CO2.
When your grow light is not super strong, light is the limiting factor in your grow - not CO2. Because of this, the extra CO2 you use won't do much in terms of increasing plant growth.
Final thoughts on calculating CO2 flow rate
Our grow room CO2 calculator should be easy enough to use, but if you aren't entirely sure about adding CO2 to your grow, you can learn more in our beginner's guide to CO2.
You can also reach out to our expert growers at 888-815-9763 and we can answer whatever questions you have and help you come up with a game plan.
