Database Storage Calculator – Total DB Size
Calculate total database storage from record count, row size, and overhead.
About This Calculator
Calculate total database storage from record count, row size, and overhead. Use the calculator above for instant results.
Worked Examples
- Raw: 5 GB | With indexes: 6.5 GB | Compressed: ~2.6 GB
Answer: ~6.5 GB / ~2.6 GB compressed
- Raw: 200 GB | With indexes: 300 GB
Answer: ~300 GB
- Raw: 100 GB | With indexes: 140 GB
Answer: ~140 GB
Who Uses This Calculator?
Estimate database storage requirements.
Plan database infrastructure.
Size database servers.
Choose cloud database tier.
Common Mistakes to Avoid
❌ Index size varies widely
Simple integer index: ~10%. Full-text index: 100%+. Multiple columns indexed: 50-100% overhead is common for OLTP.
❌ Actual size is larger than calculated
WAL/redo logs, transaction logs, temp space, and OS/filesystem overhead add 30-50% beyond the calculator estimate.
Frequently Asked Questions
How to find actual DB size?
SELECT pg_size_pretty(pg_database_size('mydb')) in PostgreSQL. EXEC sp_spaceused in SQL Server. SELECT table_schema... in MySQL.
Index vs no-index tradeoff?
More indexes = faster reads, slower writes, more storage. Index columns used in WHERE, JOIN, and ORDER BY clauses.
Database compression?
PostgreSQL TOAST, MySQL InnoDB compression, SQL Server row compression can reduce storage 30-70% for typical transactional data.