Make room for the next shelf.
This calculator multiplies your book counts by editable average file sizes, adds growth headroom, and includes the backup copies you choose. Defaults are examples, not measured averages or provider limits.
Measure a useful sample
Choose several files from each part of your collection. Text-only novels, image-heavy books, and scanned PDFs can have very different sizes. Use your sample to replace the starting assumptions.
Allow for copies and growth
Your working library and its backups occupy separate space. A format variant also adds storage even when it represents the same title. Set headroom based on how quickly you add books, not only today’s count.
Understand the units
The result uses decimal megabytes and gigabytes: 1 GB equals 1,000 MB. Some devices display binary units instead. This estimate excludes application databases, cached files, and provider-specific overhead.
The details, at a glance.
| Consider | What to look for |
|---|---|
| Book files | Count × average MB for each category |
| Headroom | Additional percentage for growth |
| Backup copies | Independent copies beyond the working library |
| Total | Working allocation × all copies |
A few things worth asking.
Why does my device show a different total?
It may use binary units or include app data, covers, caches, and other files.
Are the defaults typical file sizes?
They are editable examples only. Measure your own collection for a better estimate.
Written by Binge Reader. Our comparisons explain documented workflows and practical tradeoffs; they are not independent product benchmarks.