# Step-by-Step Guide to Calculate Fresh Air CFM

Calculating the Fresh Air CFM (Cubic Feet per Minute) for a space is essential to ensure proper ventilation and air quality. Follow these steps to accurately calculate the Fresh Air CFM required for your space.

## Step 1: Understand the Formula

The basic formula to calculate Fresh Air CFM is:

`Fresh Air CFM = (Occupant CFM + Area CFM)`

Where:

**Occupant CFM** is the amount of fresh air required per person.**Area CFM** is the amount of fresh air required per square foot of the space.

## Step 2: Gather Required Values

You will need the following values for the calculation:

**CFM per Person**: The amount of fresh air required per person. This value can vary depending on the type of space. For example, in a restaurant, it is generally around 7.5 CFM per person.**Number of Persons**: The total number of people expected to occupy the space.**CFM per Square Foot**: The amount of fresh air required per square foot. In a restaurant, this is typically around 0.06 CFM per square foot.**Area of the Space (in square feet)**: The total area of the space.

## Step 3: Calculate Occupant CFM

Use the following formula to calculate the Occupant CFM:

`Occupant CFM = CFM per Person * Number of Persons`

For example, if you have a restaurant with 50 people and the CFM per person is 7.5, the calculation would be:

`Occupant CFM = 7.5 CFM/person * 50 persons = 375 CFM`

## Step 4: Calculate Area CFM

Use the following formula to calculate the Area CFM:

`Area CFM = CFM per Square Foot * Area of the Space`

For example, if the restaurant is 2000 square feet and the CFM per square foot is 0.06, the calculation would be:

`Area CFM = 0.06 CFM/sq ft * 2000 sq ft = 120 CFM`

## Step 5: Calculate Total Fresh Air CFM

Finally, add the Occupant CFM and the Area CFM to get the total Fresh Air CFM required for the space:

`Fresh Air CFM = Occupant CFM + Area CFM`

Using the previous examples, the calculation would be:

`Fresh Air CFM = 375 CFM + 120 CFM = 495 CFM`

Therefore, the restaurant would require 495 CFM of fresh air to ensure proper ventilation.

## Conclusion

By following these steps, you can accurately calculate the Fresh Air CFM required for any space. This ensures a healthy and comfortable environment for the occupants. For more information on common mistakes to avoid during the calculation, visit our Common Mistakes in Fresh Air CFM Calculation page.