A simple Mongo Shell function to get dataSize, storageSize and indexSize for each DB

getStorageDataWithErrorCorrection.js

function getStorageDetails() {
  var db = this.db.getSiblingDB("admin");
  var totalIndexSize = 0,
      totalStorageSize = 0,
      totalDataSize = 0,
      formatSize = 1024 * 1024 * 1024;
  
  // List the databases
  var dbs = db.runCommand({ listDatabases: 1 }).databases;
  
  // Loop over and get storage stats for each database
  dbs.forEach(function(database) {
    db = db.getSiblingDB(database.name);

    print(`\nDB: ${database.name}:`);
    print(`dataSize: ${db.stats(formatSize).dataSize}`);
    print(`storageSize: ${db.stats(formatSize).storageSize}`);
    print(`indexSize: ${db.stats(formatSize).indexSize}`);

    totalDataSize += db.stats(formatSize).dataSize || 0;
    totalStorageSize += db.stats(formatSize).storageSize || 0;
    totalIndexSize += db.stats(formatSize).indexSize || 0;
  });
  
  // Show total information
  print("\nTotal:");
  print(`dataSize: ${totalDataSize}`);
  print(`storageSize: ${totalStorageSize}`);
  print(`indexSize: ${totalIndexSize}`);
}
 

getStorageDetails();

getStorageDetails.js

function getStorageDetails() {
  var db = this.db.getSiblingDB("admin");
  var totalIndexSize = 0,
      totalStorageSize = 0,
      totalDataSize = 0,
      formatSize = 1024 * 1024 * 1024;
  
  // List the databases
  var dbs = db.runCommand({ listDatabases: 1 }).databases;
  
  // Loop over and get storage stats for each database
  dbs.forEach(function(database) {
    db = db.getSiblingDB(database.name);

    print(`\nDB: ${database.name}:`);
    print(`dataSize: ${db.stats(formatSize).dataSize}`);
    print(`storageSize: ${db.stats(formatSize).storageSize}`);
    print(`indexSize: ${db.stats(formatSize).indexSize}`);

    totalDataSize += db.stats(formatSize).dataSize;
    totalStorageSize += db.stats(formatSize).storageSize;
    totalIndexSize += db.stats(formatSize).indexSize;
  });
  
  // Show total information
  print("\nTotal:");
  print(`dataSize: ${totalDataSize}`);
  print(`storageSize: ${totalStorageSize}`);
  print(`indexSize: ${totalIndexSize}`);
}
 

getStorageDetails();

getStorageDetails_ES5.js

function getStorageDetails() {
  var db = this.db.getSiblingDB("admin");
  var totalIndexSize = 0,
      totalStorageSize = 0,
      totalDataSize = 0,
      formatSize = 1024 * 1024 * 1024;
  
  // List the databases
  var dbs = db.runCommand({ listDatabases: 1 }).databases;
  
  // Loop over and get storage stats for each database
  dbs.forEach(function(database) {
    db = db.getSiblingDB(database.name);

    print("\nDB: " + database.name);
    print("dataSize: " + db.stats(formatSize).dataSize);
    print("storageSize: " + db.stats(formatSize).storageSize);
    print("indexSize: " + db.stats(formatSize).indexSize);

    totalDataSize += db.stats(formatSize).dataSize;
    totalStorageSize += db.stats(formatSize).storageSize;
    totalIndexSize += db.stats(formatSize).indexSize;
  });
  
  // Show total information
  print("\nTotal:");
  print("dataSize: " + totalDataSize);
  print("storageSize: " + totalStorageSize);
  print("indexSize: " + totalIndexSize);
}
 

getStorageDetails();