Table Size Calculator
Estimate the on-disk size of a database table from row count and row width.
About Table Size Calculator
Item count times average size gives the raw payload; the overhead percentage covers the indexes, framing and metadata that always accompany the data itself. Results are shown in binary MB and GB (1,024-based), which is what tooling reports. Storage and transfer quotas are hard limits, and a table that is 15% larger than estimated is what turns a nightly job into a failed one.
Formula
Table Size
Total bytes = Rows in the table × Average row size × (1 + overhead)
- Rows in the table
- Number of items stored or transferred
- Average row size
- Average size of one item in bytes
Worked example
With the default values below, Table Size Calculator returns Total Size of 6,141.663. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Rows in the tableminimum 0
- 20,000,000
- Average row sizeminimum 0 bytes
- 280 bytes
- Structural or index overheadaccepts 0–100 %
- 15 %
Results
- Total Size
- 6,141.663 MB
- Total Size
- 6 GiB
- Total Size
- 5.9977 GB
- Overhead Included
- 801 MiB
- Size per Row
- 0.315 KB
Step by step
- 1Values used
- 2Table Size
- 3Total Size= 6,141.663 MB
- 4Total Size= 6,440,000,000
- 5Total Size= 5.9977 GB
- 6Overhead Included= 840,000,000
- 7Size per Row= 0.315 KB
Assumptions and limits
- The result is derived only from the 3 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Table Size calculated?
Total bytes = Rows in the table × Average row size × (1 + overhead) Item count times average size gives the raw payload; the overhead percentage covers the indexes, framing and metadata that always accompany the data itself. Results are shown in binary MB and GB (1,024-based), which is what tooling reports.
Why does Table Size matter?
Storage and transfer quotas are hard limits, and a table that is 15% larger than estimated is what turns a nightly job into a failed one.
What values do I need to enter?
This calculator takes 3 inputs: Rows in the table, Average row size, Structural or index overhead. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.