stats() (Collection Statistics)
Last updated: 2026-10-09
stats() (Collection Statistics)
stats() returns collection statistics, e.g. `db.users.stats()` — document count, collection size, storage size, index count and size, plus sharding info. It is the standard tool for capacity and health assessment. Size fields are in bytes, and some metrics like document count are metadata-based estimates.
| Category | Index & Admin |
|---|---|
| MongoDB Version | 1.0+ |
| Example Language | mongosh (Shell) |
📝 Syntax
db.<collection>.stats()Returns：Stats object with count, size, storageSize, indexSizes, etc.
▶ Example
Run the commands below in your local mongosh (requires a running mongod):
// stats: inspect users size and document count
const s = db.users.stats()
print('Docs: ' + s.count + ', storage: ' + s.storageSize + ' bytes')Output：
Docs: 1000, storage: 65536 bytes📌 Notes
- Fields like count are metadata-based and may drift
- Size fields are in bytes
- Index sizes live in indexSizes, keyed by index name
🏷️ Related Tags
💡 Related Cases
More hands-on cases coming soon.
📚 Related Tutorials
❓ FAQ
QWhat unit are stats() size fields in?
ABytes. Divide storageSize by 1024*1024 to get MB.
QIs the count in stats() accurate?
AUsually close, but metadata-based and can lag under heavy writes; use countDocuments() for exactness.
QHow do I see each index's size?
ARead the indexSizes object — keys are index names, values are byte sizes.
