Percent Error Calculator

Enter the observed value and the true value to calculate percent error.

Result [Save this calculation]
Percent error =
Steps:

Percent Error =
(Vobserved − Vtrue) / Vtrue × 100

= ( − ) /

= /

= %

= % error

What Is Percent Error?

Percent error measures how far an observed value differs from the true or accepted value. It is commonly used in math, physics, chemistry, and laboratory experiments.

Percent Error Formula

Percent Error = (Observed Value − True Value) ÷ True Value × 100

Why Percent Error Can Be Negative

A negative percent error means the observed value is less than the true value. Sometimes percent error is reported as an absolute value.

Frequently Asked Questions

Is percent error always positive?
No. Percent error can be positive or negative depending on whether the observed value is greater or less than the true value.

What is absolute percent error?
Absolute percent error removes the negative sign and shows only the magnitude of error.

Is this calculator free?
Yes, this percent error calculator is completely free and works instantly.