Some utils to help you calculate distance: https://github.com/firebase/geofire-js/blob/master/src/geoFireUtils.js
And: firebase - How to run a geo "nearby" query with firestore? - Stack Overflow
Some utils to help you calculate distance: https://github.com/firebase/geofire-js/blob/master/src/geoFireUtils.js
And: firebase - How to run a geo "nearby" query with firestore? - Stack Overflow