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

FIT Rate Calculator

From Test Data
FIT ↔ MTBF

Enter your test — get FIT, λ and MTBF in one click.

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

Test your knowledge using the equation and check your answer with the calculator..

FIT = F/T * 10^9 = ?