Haversine formula

function toRad(x){
 return (x * Math.PI / 180);
}

function calculateDistance(userAddress, providerAddress){

  if(providerAddress && userAddress){
    const lon1 = providerAddress.lat;
    const lat1 = providerAddress.lng;

    const lon2 = userAddress.lat;
    const lat2 = userAddress.lng;

    const R = 6371;

    const x1 = lat2 - lat1;
    const dLat = toRad(x1);
    const x2 = lon2 - lon1;
    const dLon = toRad(x2)
    const angle = Math.sin(dLat / 2) * Math.sin(dLat / 2) +
      Math.cos(toRad(lat1)) * Math.cos(toRad(lat2)) *
      Math.sin(dLon / 2) * Math.sin(dLon / 2);
    const arc = 2 * Math.atan2(Math.sqrt(angle), Math.sqrt(1 - angle));
    const distance = R * arc;

    return Math.ceil(distance || 0);
  }
  return 0;
}