---
title: rootMeanSquaredError
framework: createml
role: symbol
role_heading: Instance Property
path: createml/mlregressormetrics/rootmeansquarederror
---

# rootMeanSquaredError

A common metric used to determine the deviation between correct and predicted values.

## Declaration

```swift
var rootMeanSquaredError: Double { get }
```

## Mentioned in

Improving Your Model’s Accuracy

## Discussion

Discussion The rootMeanSquaredError is calculated by taking the square-root of the average squared distance between the correct and predicted value.

## See Also

### Understanding the model

- [maximumError](createml/mlregressormetrics/maximumerror.md)