Can I solve for different variables?

Yes! This calculator supports reverse solving. You can solve for: Room length, Room width, Ceiling height, Floor area, Room volume, Current CO₂ (ppm), Target CO₂ (ppm), CO₂ volume required, Injection time, Flow rate.

What units can I use?

This calculator supports multiple unit systems. Select your preferred units from the dropdown menus next to each input field.

CO₂ Grow Room Calculator

Determine how much CO₂ to inject into a grow room and the flow rate required over a chosen time window.

Formula shown6 inputs definedUpdated Nov 2025By CalcuTotal TeamFree, no sign-up

Quick Summary

Use this when you need:

Size a CO₂ tank or bag system for a sealed grow tent
Figure out how long to open a regulator to bump the room from 400 ppm to a setpoint
Compare different ceiling heights or room footprints when planning enrichment gear

You’ll need:Room length, Room width, Ceiling height, Current CO₂ (ppm), and 2 more

You’ll get:Floor area, Room volume, CO₂ volume required, Flow rate

How this is calculated

Formula:

room_volume = length * width * height; needed_CO2 = (target_ppm - current_ppm)/1e6 * room_volume; flow_rate = needed_CO2 / time_minutes * 60

In plain language:

We compute cubic room volume from geometry, convert the ppm delta into an absolute CO₂ volume fraction, then divide by the injection window (in minutes) to get the continuous flow requirement.

The formula is always visible so you can verify the math and explain your numbers to anyone who asks.

What these terms mean

Room length

Room length used in the calculation.

Room width

Room width used in the calculation.

Ceiling height

Ceiling height used in the calculation.

Floor area

Floor area used in the calculation.

Room volume

Room volume used in the calculation.

Current CO₂ (ppm)

Current CO₂ (ppm) used in the calculation.

Target CO₂ (ppm)

Target CO₂ (ppm) used in the calculation.

CO₂ volume required

CO₂ volume required used in the calculation.

Injection time

Injection time used in the calculation.

Flow rate

Flow rate used in the calculation.

When to use this calculator

Size a CO₂ tank or bag system for a sealed grow tent
Figure out how long to open a regulator to bump the room from 400 ppm to a setpoint
Compare different ceiling heights or room footprints when planning enrichment gear

Last updated: November 19, 2025

CO2 grow room calculator explained

Sealed grow rooms often enrich carbon dioxide to 800-1,200 ppm to boost photosynthesis. This calculator multiplies room dimensions to find volume, converts the ppm difference you want into an absolute CO2 volume, and then divides by the injection window to give the continuous flow rate required from a regulator or generator.

How the conversion works

Volume: $V = L \\times W \\times H$ (converted to cubic meters).
CO2 needed: PPM is parts per million, so the absolute volume fraction equals $(\\text{target} - \\text{current}) / 10^6$ . Multiply by $V$ to get cubic meters (or cubic feet) of pure CO2.
Flow rate: Divide the required CO2 volume by the injection time (minutes) and multiply by 60 to report per hour flow.

\\text{flow} = \\frac{(\\text{target} - \\text{current})}{10^6} \\times \\frac{V}{t} \\times 60

Units and conversions

Quantity	Units	Notes
Length, width, height	m, ft	The calculator converts to cubic meters internally.
CO2 ppm	ppm	Enter ambient (~400 ppm) and target setpoint (up to 1,500 ppm for most crops).
CO2 volume	m³, ft³	Represents pure CO2 you must add to the room.
Flow rate	m³/h, L/min	L/min is convenient for flowmeters; m³/h helps when sizing burners or cylinders.

Worked examples

Metric grow tent
4 x 3 x 2.5 m tent, raise from 400 ppm to 1,200 ppm in 10 minutes.

V = 30\\ \\text{m}^3,\\quad \\Delta ppm = 800

Needed CO2 $= 800/10^6 \\times 30 = 0.024$ m³. Flow $= 0.024 / 10 \\times 60 = 0.144$ m³/h (144 L/h).

Imperial room
12 x 10 x 8 ft room, bump from 450 to 1,500 ppm in 5 minutes.

V = 960\\ \\text{ft}^3,\\quad \\Delta ppm = 1{,}050

Needed CO2 $= 1{,}050/10^6 \\times 960 = 1.008$ ft³. Flow $= 1.008 / 5 \\times 60 = 12.1$ ft³/h (about 5.7 L/min).

Tips and pitfalls

Only enrich sealed rooms; leaks waste gas and can trigger alarms in shared spaces.
Use a controller with CO2 and temperature interlocks so enrichment pauses when lights are off or temps spike.
Recalculate volume whenever you install new tables or lower ceilings; room volume drives the entire formula.
Never exceed crop-appropriate ppm thresholds; most horticultural references cap at 1,500 ppm during lights on.

References and further reading

Frequently Asked Questions

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Calculator info

Version:: v1.0.0
Last reviewed:: Nov 15, 2025
Sensitivity:: low
References:: 1

Last updated: November 19, 2025

CO2 grow room calculator explained

How the conversion works

Volume: $V = L \\times W \\times H$ (converted to cubic meters).
CO2 needed: PPM is parts per million, so the absolute volume fraction equals $(\\text{target} - \\text{current}) / 10^6$ . Multiply by $V$ to get cubic meters (or cubic feet) of pure CO2.
Flow rate: Divide the required CO2 volume by the injection time (minutes) and multiply by 60 to report per hour flow.

\\text{flow} = \\frac{(\\text{target} - \\text{current})}{10^6} \\times \\frac{V}{t} \\times 60

Units and conversions

Quantity	Units	Notes
Length, width, height	m, ft	The calculator converts to cubic meters internally.
CO2 ppm	ppm	Enter ambient (~400 ppm) and target setpoint (up to 1,500 ppm for most crops).
CO2 volume	m³, ft³	Represents pure CO2 you must add to the room.
Flow rate	m³/h, L/min	L/min is convenient for flowmeters; m³/h helps when sizing burners or cylinders.

Worked examples

Metric grow tent
4 x 3 x 2.5 m tent, raise from 400 ppm to 1,200 ppm in 10 minutes.

V = 30\\ \\text{m}^3,\\quad \\Delta ppm = 800

Needed CO2 $= 800/10^6 \\times 30 = 0.024$ m³. Flow $= 0.024 / 10 \\times 60 = 0.144$ m³/h (144 L/h).

Imperial room
12 x 10 x 8 ft room, bump from 450 to 1,500 ppm in 5 minutes.

V = 960\\ \\text{ft}^3,\\quad \\Delta ppm = 1{,}050

Needed CO2 $= 1{,}050/10^6 \\times 960 = 1.008$ ft³. Flow $= 1.008 / 5 \\times 60 = 12.1$ ft³/h (about 5.7 L/min).

Tips and pitfalls

Only enrich sealed rooms; leaks waste gas and can trigger alarms in shared spaces.
Use a controller with CO2 and temperature interlocks so enrichment pauses when lights are off or temps spike.
Recalculate volume whenever you install new tables or lower ceilings; room volume drives the entire formula.
Never exceed crop-appropriate ppm thresholds; most horticultural references cap at 1,500 ppm during lights on.

Quick Summary

Calculator Tool

How this is calculated

What these terms mean

Room length

Room width

Ceiling height

Floor area

Room volume

Current CO₂ (ppm)

Target CO₂ (ppm)

CO₂ volume required

Injection time

Flow rate

When to use this calculator

CO2 grow room calculator explained

How the conversion works

Units and conversions

Worked examples

Tips and pitfalls

References and further reading

Frequently Asked Questions

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Was this calculator helpful?

Found an error?

Calculator info

CO2 grow room calculator explained

How the conversion works

Units and conversions

Worked examples

Tips and pitfalls

References and further reading

Frequently Asked Questions

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