---
title: "CalculateTileZoomFunction | JavaScript maps SDK"
description: "Documentation for MapTiler SDK"
---

> For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL.

# Type Alias CalculateTileZoomFunction

CalculateTileZoomFunction: (  
    requestedCenterZoom: number,  
    distanceToTile2D: number,  
    distanceToTileZ: number,  
    distanceToCenter3D: number,  
    cameraVerticalFOV: number,  
) \=> number

Function to define how tiles are loaded at high pitch angles

#### Type Declaration

-   -   (  
            requestedCenterZoom: number,  
            distanceToTile2D: number,  
            distanceToTileZ: number,  
            distanceToCenter3D: number,  
            cameraVerticalFOV: number,  
        ): number
    -   #### Parameters
        
        -   requestedCenterZoom: number
            
            the requested zoom level, valid at the center point.
            
        -   distanceToTile2D: number
            
            2D distance from the camera to the candidate tile, in mercator units.
            
        -   distanceToTileZ: number
            
            vertical distance from the camera to the candidate tile, in mercator units.
            
        -   distanceToCenter3D: number
            
            distance from camera to center point, in mercator units
            
        -   cameraVerticalFOV: number
            
            camera vertical field of view, in degrees
            
        
        #### Returns number
        
        the desired zoom level for this tile. May not be an integer.