Free Database Storage Estimate calculator with clear step-by-step results.
Row count times average row size gives heap size, but indexes routinely add 30-60% on top and are what usually breaks a storage forecast. Compounding row growth over the projection period gives the figure to provision volumes and backup capacity against.
Current size
Bytes = rows x average row bytes x (1 + index overhead)
Projected size
Projected = rows x (1 + monthly growth)^months x row bytes x (1 + index overhead)
Divide the table's on-disk heap size by its row count using your engine's catalog views. Estimating from column types ignores per-row headers, alignment padding and page free space.
No. Transaction logs, point-in-time recovery archives and full backup copies commonly need one to three times the live data size again.