How do I read my DNA Paternity Test Results?

How to Read Your Results

In your test report, turn to Page 2. You will see a chart displaying the DNA profiles for each person tested. The data displayed in the DNA profile chart may look something like this:

At the bottom of the table, you will see a "Combined Paternity Index, and Probability of Paternity". These are the values you want to focus on.

Combined Paternity Index

The Combined Paternity Index (CPI) value is calculated by multiplying the calculated paternity index values together. The CPI value is a measure of the overall strength of the genetic evidence. It represents how many times more likely it is that the tested alleged father is the true biological father compared to a randomly selected man in the population.

Probability of Paternity

The probability of paternity is calculated from the CPI, and it is generally considered to be the final result of a paternity test. A CPI value of 0 corresponds to a probability of paternity of 0%. A CPI value that is greater than 1000 corresponds to a probability of paternity of greater than 99.99%.

So what does this mean?

In a DNA Paternity Test, your test report will indicate one of two possible outcomes:

If the alleged father IS NOT the true biological father, your report is expected to state:

PROBABILITY OF PATERNITY: 0

If the alleged father IS the true biological father, your report is expected to state:

PROBABILITY OF PATERNITY: >99.99%