Enter the number of failures and the total time (hrs) into the FIT Rate Calculator. The calculator will evaluate the FIT Rate.

FIT Rate Formula

The following two example problems outline the steps and information needed to calculate the FIT Rate.

FIT = F/T * 10^9
• Where FIT is the FIT Rate (failures per one billion device hours)
• F is the number of failures
• T is the total time (hrs)

To calculate the FIT rate, divide the number of failures by the total time, then multiply by 1 billion.

How to Calculate FIT Rate?

The following example problems outline how to calculate FIT Rate.

Example Problem #1:

1. First, determine the number of failures.
• The number of failures is given as: 3.
2. Next, determine the total time (hrs).
• The total time (hrs) is provided as: 100,000.
3. Finally, calculate the FIT Rate using the equation above:

FIT = F/T * 10^9

The values provided above are inserted into the equation below and computed.

FIT = 3/100,000 * 10^9 = 30,000 (failures per one billion device hours)

Example Problem #2:

For this problem, the variables required are provided below:

number of failures = 6

total time (hrs) = 200,000