I'm having trouble figuring out after how many frames the animation completes in order to create a perfect loop. I'm currently recording my canvas in 60 fps. Any ideas?

for (x = 0; x < pg.width; x += 2) {
    for (y = 0; y < pg.height; y += 2) {
      let csize = map(sin(x+y+frameCount/10), -1, 1, 2, 20);
      if (a[x][y] > 0) {
        rect(x*2-csize/2, y*2-csize/2, csize);
    }
  }
}