Email Archive Sizing Calculator

Input Mode

By daily emails + average size By monthly raw volume (GB)

Average Email Size (KB)

Emails per Day

Monthly Raw Volume (GB)

Deduplication Gain (%)

{{ dedup }}%

Compression Gain (%)

{{ compression }}%

📊 Results

Raw monthly volume: {{ formatNumber(rawMonthly) }} GB
After deduplication: {{ formatNumber(afterDedup) }} GB (saved {{ dedupSavingsPct.toFixed(1) }}%)
After compression: {{ formatNumber(finalMonthly) }} GB (extra saved {{ compressionSavingsPct.toFixed(1) }}%)
Total reduction: {{ totalSavingsPct.toFixed(1) }}%
Yearly storage need: {{ formatNumber(finalYearly) }} GB

Deduplication:
- Message-ID dedup typically saves 5–15%

- Attachment dedup (logos, forms, policies) can save 25–60%.

- Combined: often 30–55% reduction before compression.
Compression:
- Text/HTML compress well, docs moderate, images/PDFs less

- Typically adds another 15–30% savings on the remaining data.
Overall effect:
Expect total reduction of 50–70% compared to raw volume.

Site #1
- 8-9 million emails

- 25 GB index db

- 23 GB mysql db

- 200 GB stored emails
Site #2
- 2.5 million emails

- 9 GB index db

- 10 GB mysql db

- 700 GB stored emails
Site #3
- 25 million emails (11 millions are duplicates)

- 26 GB index db

- 26 GB mysql db

- 3.7 TB raw volume

- 1 TB stored volume

- 72% deduplication+compression gains
Site #4
- 44 million emails (2.3 millions are duplicates)

- 43 GB index db

- 80 GB mysql db

- 9 TB raw volume

- 3.7 TB stored volume

- 58% deduplication+compression gains