Open your terminal then open Mongo Shell
mongo
Select your database
use myDbName
Now paste the following code:
// Get collection names
var collectionNames = db.getCollectionNames()
var col_stats = [];
// Get stats for every collections
collectionNames.forEach(function (n) {
col_stats.push(db.getCollection(n).stats());
});
// Print
for (var item of col_stats) {
print(`${item['ns']} | size: ${item['size']}
(${(item['size']/1073741824).toFixed(2)} GB) | storageSize: ${item['storageSize']}
(${(item['storageSize']/1073741824).toFixed(2)} GB)`);
}
Reference: https://stackoverflow.com/a/61733956/3380387