Enter the exact or theoretical mass and the measured mass into the calculator to determine the mass accuracy.

## Mass Accuracy Formula

The following formula is used to calculate a mass accuracy.

%A = 100 – | mm – em | / em * 100

- Where %A is the mass accuracy (%)
- mm is the measured mass
- em is the exact mass

## Mass Accuracy Definition

Mass accuracy is defined as the closeness or proximity of a measurement of mass to the exact or theoretical mass of an object or material in question.

## How to calculate mass accuracy in PPM?

To calculate mass accuracy in ppm, convert each of the measured masses to PPM using this calculator. Then return and use the formula above to calculate the mass accuracy.

## What is mass error?

Mass error, or error mass, is a measure of the total percentage difference in a measured mass from the expected or theoretical mass that one should find.

## Mass Accuracy Example

How to calculate mass accuracy?

**First, determine the measured mass.**Determine the value of the mass when measured.

**Next, calculate the theoretical mass.**Calculate the theoretical mass of the substance.

**Finally, calculate the mass accuracy.**Calculate the mass accuracy using the formula above.

## FAQ

**What is an exact mass?**

An exact mass is the calculated mass of an ion whose elemental formula, isotopic composition, and charge state are known.