HVAC & Airflow

CFM to MMBtu Calculator

Convert airflow heating/cooling duty to MMBtu/hr.

Enter your values

Enter the airflow in CFM.

Enter the temperature difference in F.

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.

Results
Duty
0.216 MMBtu/hr
In BTU/hr
216,000
In tons (if cooling)
18

Quick answer

Airflow heating or cooling duty in MMBtu/hr equals 1.08 x CFM x temperature difference, divided by one million.

MMBtu/hr = (1.08 x CFM x dT) / 1,000,000

At a glance

What it doesConvert airflow heating/cooling duty to MMBtu/hr.
CategoryHVAC & Airflow
Inputs neededAirflow, Temperature difference
Main outputDuty
FormulaMMBtu/hr = (1.08 x CFM x dT) / 1,000,000
CostFree — no sign-up, no download

How to use the CFM to MMBtu Calculator

  1. 1Enter the system's airflow in CFM.
  2. 2Enter the temperature difference across the coil or heater.
  3. 3The result converts sensible BTU/hr directly to MMBtu/hr (millions of BTU per hour).

Inputs explained

Airflow(CFM)
Enter the airflow in CFM.
Temperature difference(F)
Enter the temperature difference in F.

Worked example

Using the values the calculator loads with:

Inputs

  • Airflow5000 CFM
  • Temperature difference40 F

Results

  • Duty0.216 MMBtu/hr
  • In BTU/hr216,000
  • In tons (if cooling)18

Frequently asked questions

When would I use MMBtu instead of BTU?

MMBtu is common in utility billing, boiler plant capacity and large commercial/industrial energy accounting.

Does this include latent heat?

No — this is sensible heat only; add latent load separately for full cooling/heating duty.

What do I need to enter into the CFM to MMBtu Calculator?

Just 2 values: airflow, temperature difference. 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 CFM to MMBtu Calculator work out the answer?

Airflow heating or cooling duty in MMBtu/hr equals 1.08 x CFM x temperature difference, divided by one million. It applies the formula MMBtu/hr = (1.08 x CFM x dT) / 1,000,000 and shows the working so you can check each step by hand.

Is the CFM to MMBtu 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.