Enter the measured value and the true value into the calculator to determine the percent deviation.

- Percent Error Calculator
- Percentage Difference Calculator
- Relative Error Calculator
- Relative Standard Deviation Calculator

## Percent Deviation Formula

The following formula is used to calculate a percent deviation.

D =( X_{m} – X_{t} ) / X_{t} * 100

- Where D is the percent deviation (%)
- X
_{m}is the measured value - X
_{t}is the true value

## Percent Deviation Definition

A percent deviation is defined as the percentage difference between a measure value and a true value.

## Percent Deviation Example

How to calculate percent deviation?

**First, determine the measured value.**Take the measured value measurement.

**Next, determine the true value.**Calculate the theoretical true value.

**Finally, calculate the percent deviation.**Calculate the percent deviation using the formula above.

## FAQ

**What is a percent deviation?**

A percent deviation is the variance of a given value from a known true value presented as a ratio of the percentage of the true value.