Biology
Find how much CO₂ raises a sealed grow room from ambient to your target ppm.
Your inputs
Change any value — everything updates instantly.
Inside length of the sealed room.
Inside width.
Floor to ceiling.
Common enrichment targets are 1,000–1,500 ppm.
Outdoor air is roughly 400 ppm.
Try an example
CO₂ to add
0.512 ft³
This means about 14.5 litres of CO₂ lifts the room to your target.
What you are seeing
The green fill rises as CO₂ is released into the room.
The dashed line is ambient air at 400 ppm.
Reaching 1,200 ppm needs 0.512 ft³ of CO₂.
Room volume
640 ft³
Length × width × height.
CO₂ in litres
14.5 L
Same amount in litres.
Increase needed
800 ppm
Target minus ambient.
Per 100 ft³
0.08 ft³
CO₂ per 100 ft³ of room per 100 ppm... scales linearly.
Result explanation: CO₂ enrichment
0.512 ft³ (14.5 L) of CO₂.
Real-life comparison: A target of 1,500 ppm would need 0.704 ft³.
Low, normal or high? Within the commonly used enrichment range.
CO₂ needed against target ppm
How to read this chart: CO₂ rises in a straight line with the target. The red dot is your target.
Multiplies the room volume by the ppm increase to find the CO₂ volume.
0.512 ft³ of CO₂.
Works only in a sealed room — ventilation removes it quickly.
Plants use CO₂, so levels fall and need topping up.
Room volume times the ppm increase, scaled by a million.
CO₂ (ft³) = room ft³ × (target − ambient) ÷ 1,000,000
Symbols
Why this formula works
1 ppm of a volume is one millionth of that volume.
Unit check
ft³ × ppm ÷ 1e6 = ft³ ✓
Worked example
Common mistakes
Add about 0.512 ft³ (14.5 L) of CO₂.
Levels under ~1,500 ppm are used in greenhouses, but occupied spaces need ventilation and monitoring.
Plants consume CO₂ in light and any leak or fan removes it.
No — without light there is no photosynthesis.
Outdoor air is roughly 400–420 ppm; indoor air can be higher.
Reviewed 2026-09-25 · Next review 2027-09-25
Important limitation. Instant-fill estimate; ongoing consumption and leaks are not included.
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