File Size Calculator
Add up multiple file sizes, mix units, apply quantities, and estimate total storage or transfer size. Useful for uploads, cloud backups, media libraries, and project packaging.
Automatically chooses a readable unit such as MB, GB, MiB, or GiB for the final total.
Add rows for each file type or batch. Example: 250 images at 6 MB each, 12 videos at 1.4 GiB each, and 1 archive at 850 MB.
| Label | Size value | Unit | Quantity | Row total | Action |
|---|
| Label | Input | Qty | Row bytes | Readable row total |
|---|
| Unit | System | Total value |
|---|
Privacy: calculations run locally in your browser. No file-size data is stored or transmitted.
How to use this result
The calculated total helps estimate storage requirements, upload limits, and transfer times.
- Decimal vs Binary: Storage devices use decimal, operating systems often show binary.
- Best-fit unit: Displays the most readable format (e.g. GB instead of MB).
- Exact bytes: Useful for technical calculations or API limits.
Use cases
- Estimating storage requirements
- Checking upload size limits
- Comparing file sizes across formats
How it works
This tool calculates total file size based on input values and converts between units.
- Input size: Base file size
- Unit conversion: KB, MB, GB
- Total size: Aggregated result
How to interpret: Use the result to estimate storage usage or upload limits.
Examples
- 250 × 6 MB → estimate a photo library total
- 12 × 1.4 GiB → estimate a video backup batch
- 3 × 850 MB + 1 × 12 GiB → compare project packaging totals
FAQ
- What does the file size calculator do?
It adds multiple file sizes together, optionally multiplying each row by a quantity. This helps estimate storage, upload size, backup size, and transfer totals.
- Can I mix units like MB and GiB?
Yes. Each row can use a different unit. The calculator converts each row to bytes first, then computes the total.
- What is the difference between decimal and binary totals?
Decimal units are based on powers of 1000, while binary units are based on powers of 1024. The same byte total can be displayed differently in each system.
- Can I calculate repeated files?
Yes. Each row includes a quantity field, so you can calculate totals such as 50 photos at 6 MB each or 12 videos at 1.4 GiB each.
- Is my data stored anywhere?
No. The calculator runs locally in your browser and does not store or transmit your entries.