Percent Error Calculator.
Compare an experimental (observed) value to a theoretical (accepted) value and get percent, absolute, and relative error.
Experimental is lower than theoretical by 0.01.
What Is Percent Error?
Percent error measures how far an experimental result is from an accepted or theoretical value. This free percent error calculator also shows absolute error and relative error for lab reports and homework.
Percent Error Formula
Absolute error = |Exp − Theo|. Relative error = absolute error ÷ |Theo|.
Frequently Asked Questions (FAQs)
What is the percent error formula?
Percent error = |experimental − theoretical| / |theoretical| × 100. Absolute error is the absolute difference; relative error is that difference divided by |theoretical|.
Can percent error be negative?
Standard percent error uses absolute values, so it is non-negative. This tool notes separately whether the experimental value was higher or lower.
What if the theoretical value is zero?
Percent and relative error are undefined (division by zero). Absolute error can still be calculated.