# How to calculate percent error

So Rømer was quite a bit off by our standards today, but considering he came up with this estimate at a time when a majority of respected astronomers, like Cassini, still believed that the speed of light was infinite, his conclusion was an outstanding contribution to the field of astronomy. Calculating percent is a fundamental math skill, whether you're taking a class or just living life! Percentages are used to make car and house payments, calculate tips and pay taxes on goods. This website uses cookies to improve your experience while you navigate through the website. Out of these cookies, the cookies that are categorized as necessary are stored on your browser as they are as essential for the working of basic functionalities of the website. This free percent error calculator computes the percentage error between an observed value and the true value of a measurement. Explore various other math calculators. To see all my Chemistry videos, check out How to calculate error and percent error. Math explained in easy language, plus puzzles, games, quizzes, worksheets and a forum. For K-12 kids, teachers and parents. Learn how to calculate percent error on a set of data as well as on individual results. NOTE: Even though in this example the output came in negative but with symbols “|” which stands for absolute value and hence the number +21 is derived. Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. jessica bedford September 23, 2017 at 3:20 pm. okay say you have two different percent errors, because of a word problem were there the end result id two groups of percent errors, how do you know which one is the accurate one.