Tenant Migration Services

Interactive migration worksheet

Estimate the bulk-copy work before planning a cutover.

This calculation turns your own mailbox counts and transfer-speed assumption into a testable workload estimate. It cannot tell you what Microsoft, Google or a migration vendor will actually allow in your tenant.

Set the assumptions

Replace the example values with inventory figures. No information is submitted or stored.

The 20 GB/hour default is an editable illustration, not our observed throughput or a vendor benchmark. Validate your effective speed using a representative pilot.

Estimated mail data320 GB
Bulk-copy hours, without reserve16 hours
Copy plus reserve20 hours
Transfer-day allowance3 transfer days

Make the estimate useful

Run a representative pilot with the actual source, destination and migration method. Record data moved, duration, throttling, exceptions and permission outcomes. Then replace the assumed aggregate speed above. Compare the result with your available migration windows, not just an ideal uninterrupted transfer.

For Microsoft 365 cross-tenant moves, check the relevant mailbox migration prerequisites and licensing separately from this arithmetic. No credentials or mailbox contents are needed for the calculation.

Cross-tenant mailbox prerequisites ยท Acceptance checklist