Grow Room CO2 Calculator
Calculate how much CO2 to add per dose and estimate tank runtime for your room.
Fresh outdoor air is roughly 400 to 420 ppm.
Most growers target 1,200 to 1,500 ppm during lights on. Do not exceed 2,000 ppm.
Typical range is 6 to 24 doses during the light cycle.
Leakier rooms lose CO2 between doses, so daily use goes up.
CO2 per dose
0.00
lbs
- Room volume
- 0 ft³
- ppm rise per dose
- 0 ppm
- CO2 per dose
- 0.00 ft³
- CO2 per day
- 0.00 lbs
- Estimated tank life
- 0 days
Run CO2 only during the light cycle. Plants cannot use it in the dark.
CO2 target reference by stage
| Stage | Target ppm |
|---|---|
| Propagation / seedling | 400 to 600 |
| Vegetative | 800 to 1,200 |
| Early flower | 1,200 to 1,500 |
| Late flower | 800 to 1,000 |
| Maximum safe level | 2,000 |
Formula: CO2 (ft³) = room volume (ft³) × (target ppm − ambient ppm) ÷ 1,000,000. Pounds = ft³ ÷ 8.7.