What Math Is Involved in Forensic Science?

By Jenny MacKay ; Updated June 05, 2017
Forensic scientist

Forensic science is any branch of science used to analyze crime scene evidence for a court of law. All science uses math concepts and equations, and forensic scientists are well educated in mathematical concepts they use to analyze evidence from crime scenes.

The Facts

It is impossible to analyze forensic evidence scientifically without math. One of the main things crime scene investigators do is collect, measure and document evidence. Their data help forensic scientists perform calculations and determine the facts of a crime. Math makes it possible to show proof of what occurred during a crime in data and numbers.


One area of math that is crucial to forensic science is taking precise measurements at a crime scene. Knowing the exact length of a shoe print could later help rule out crime suspects whose shoes are the wrong size, for example. Forensic scientists need exact measurements of everything at a crime scene in order to perform scientific calculations properly. Investigators spend a great deal of time measuring distance, weight, temperature, volume and other aspects of evidence to get the numbers correct.


Forensic scientists use not only measurements, but proportions in their analyses. If a human leg bone is discovered in an unmarked grave, for example, forensic scientists use math equations to determine what proportion, or percentage, of a person’s overall height the leg bone would be. Once they know that, they can determine how tall the person was and whether it was a child or adult. Proportions are one way math is involved in forensic science.


Trigonometry, the study and measurement of triangles, is another common use of math in forensic science. Blood spatter analysts, for example, use trigonometry in their study of how blood from a human injury splatters on a wall or other surface. They draw lines from the victim’s body to the blood spatter, then use angles and distances to calculate the third point of the triangle: the person who struck the victim, where the attacker was standing, how hard he must have hit the victim and more.


Probability is a measurement of the likelihood that a specific event will occur under certain conditions. Forensic scientists often use probabilities to explain how likely it is that their findings are correct. For example, a forensic biologist who has compared a suspect’s DNA to DNA from a fluid sample found at a crime scene will tell the jury the probability, or likelihood, that the DNA samples are from the same person: perhaps the probability the two samples did not come from the same person is 1 in 100 billion. Explaining findings to juries using probabilities is a common way math is applied to forensic science.


Math is fundamental to all kinds of science, and whether a forensic scientist specializes in biology, chemistry, computers or any other scientific branch, math will be central to the crime-solving job. As more is learned about math and science and as new scientific discoveries are constantly being made, math will take on even larger roles in forensic science. In the future, forensic scientists in any discipline will need an increasingly strong educational background in math.

About the Author

Jenny MacKay has been a writer for more than 10 years. She is the author of 23 nonfiction books for young adults, as well as a contributor for newspapers and magazines. She has a B.A. in English from the University of Nevada, Reno, and an M.F.A. in creative writing from National University.