ArrayIndexOutOfBoundsException when the array index I ask doesn't go out of bounds

The problem I keep having is that it says java.lang.ArrayIndexOutOfBoundsException: 165

165 is the number of values it should actually contain.

I tried changing the length of the integer array to a bigger number but it kept giving me the error, be it with a bigger number.

I printed everything out to see if maybe the problem was my for loop, but everything there seems fine (does 165 arrays with the right numbers in them)

I can't see where the problem is.

public int[][] getTilePositionsIn(int pixelLeft, int pixelBottom, int pixelRight, int pixelTop){
    int starterTileX = pixelLeft/getTileLength();
    if (starterTileX < 0)
        starterTileX = 0;
    System.out.println(starterTileX);
    int starterTileY = pixelBottom/getTileLength();
    if (starterTileY < 0)
        starterTileY = 0;
    System.out.println(starterTileY);
    int tileLength = getTileLength();
    int blockWidth = pixelRight - pixelLeft + 1;
    int widthInTiles = blockWidth/tileLength +1;
    int blockHeight = pixelTop - pixelBottom + 1;
    int heightInTiles = blockHeight/tileLength +1;
    int numberOfTiles = widthInTiles * heightInTiles;
    System.out.println(widthInTiles);
    System.out.println(heightInTiles);
    System.out.println(numberOfTiles);
    int[][] tiles = new int[numberOfTiles][2];

    for (int y = 0; y <= heightInTiles; y++) {
        for (int x = 0; x <= widthInTiles; x++) {
            int index = y*widthInTiles + x;
            System.out.println(index);
            tiles[index][0] = x;
            tiles[index][1] = y;
            System.out.println(Arrays.toString(tiles[index]));
        }
    }
    return tiles;
}