Data Center CFM per kW Calculator
Rack airflow from IT load and delta T.
Enter your values
Enter the it load in kW.
Enter the temperature rise in °F.
Enter the number of racks you are working with.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- CFM per kW
- 158
- Airflow per rack
- 1,264 CFM
- Total room airflow
- 12,637 CFM
- Total IT load
- 80 kW
- Cooling required
- 22.7 tons
Quick answer
IT equipment needs roughly 126 CFM per kW at a 20°F rise, scaling inversely with the delta T you design for.
CFM = kW x 3412 / (1.08 x ΔT °F)
At a glance
| What it does | Rack airflow from IT load and delta T. |
|---|---|
| Category | HVAC & Airflow |
| Inputs needed | IT load, Temperature rise, Number of racks |
| Main output | CFM per kW |
| Formula | CFM = kW x 3412 / (1.08 x ΔT °F) |
| Cost | Free — no sign-up, no download |
How to use the Data Center CFM per kW Calculator
- 1Enter the average IT load per rack in kW.
- 2Choose the delta T across the equipment — 20°F is common, 30°F for containment designs.
- 3Make sure the CRAC units can deliver the total airflow, not just the tonnage.
Inputs explained
- IT load(kW)
- Enter the it load in kW.
- Temperature rise(°F)
- Enter the temperature rise in °F.
- Number of racks
- Enter the number of racks you are working with.
Worked example
Using the values the calculator loads with:
Inputs
- IT load8 kW
- Temperature rise20 °F
- Number of racks10
Results
- CFM per kW158
- Airflow per rack1,264 CFM
- Total room airflow12,637 CFM
- Total IT load80 kW
- Cooling required22.7 tons
Frequently asked questions
Why does delta T matter so much?
Raising delta T from 20 to 30°F cuts required airflow by a third, saving large amounts of fan energy.
Containment?
Hot or cold aisle containment prevents recirculation and lets you run higher supply temperatures.
What do I need to enter into the Data Center CFM per kW Calculator?
Just 3 values: it load, temperature rise, number of racks. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Data Center CFM per kW Calculator work out the answer?
IT equipment needs roughly 126 CFM per kW at a 20°F rise, scaling inversely with the delta T you design for. It applies the formula CFM = kW x 3412 / (1.08 x ΔT °F) and shows the working so you can check each step by hand.
Is the Data Center CFM per kW Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.