Solved Fastest way to calculate if entity is in a sphere?

What's the fastest way to calculate if an entity is in a sphere? I'm currently using this method:

Code:

    public boolean isEntityInSphere(final Entity entity) {
        return SPHERE_CENTER_VECTOR.distance(entity.getLocation().toVector()) <= SPHERE_RADIUS;
    }

but I need block precision, not coordinate, and currently on the border of the sphere half of blocks are protected while the other half isn't.

edit:Got it, mix of getting the entity's block location and ceiling the distance.