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# estimatedScaleFactor

A factor between the initial size and the estimated physical size.

```
var estimatedScaleFactor: CGFloat { get }
```

## Discussion

The default value is 1.0, which means that a version of this image that ARKit recognizes in the physical environment exactly matches its reference image [`physicalSize`](/documentation/ARKit/ARReferenceImage/physicalSize).

Otherwise, ARKit automatically corrects the image anchor’s transform when `estimatedScaleFactor` is a value other than 1.0. This adjustment in turn, corrects ARKit’s understanding of where the image anchor is located in the physical environment.

See [`automaticImageScaleEstimationEnabled`](/documentation/ARKit/ARWorldTrackingConfiguration/automaticImageScaleEstimationEnabled).

---

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