What Microsoft 365 Backup will actually cost you
Microsoft charges $0.15 per GB per month of protected content. The bill is driven by archives, recycle bins and file versions that don't appear in the usage reports most people check. Put your numbers in and see the whole thing.
Your tenant
Start with seats and average sizes. Rough numbers are fine — you can refine them later.
These three are estimates, not measurements
The parts nobody counts
Archives, recycle bins and versions are billable under native backup but are not reflected in the standard usage reports. They are usually why a quote comes in higher than expected.
Scoping and growth
Native pricing rewards protecting less. Most tenants should scope per site and mailbox rather than protect everything.
Compare with other tools
Pick up to 4 products to cost against the same tenant. List prices are the vendor's own published figure; type over one to use your quote.
| Option | Per month | Per year | Per user | Teams | Retention | Copy kept | Break-even |
|---|---|---|---|---|---|---|---|
| Native: protect everything | $2,738 | $32,858 | $9.13 | No | 3, 6, 12 or 24 months | Inside Microsoft 365 | — |
| Native: scoped policy | $1,440 | $17,279 | $4.80 | No | 3, 6, 12 or 24 months | Inside Microsoft 365 | — |
| Lowest monthly cost for these inputs List price, verified · source Rate verified · source |
Lowest monthly cost is a statement about these inputs, not a recommendation: Teams coverage, retention and where the copy lives differ, and a column showing “—” is one we have not confirmed against the vendor's own page. Shared mailboxes are not costed because the calculator doesn't take them as an input. BackupGap doesn't sell backup and earns nothing from any option here.
Why this number is usually wrong the first time
Microsoft publishes a pricing calculator, but it's a spreadsheet you download and fill in by hand after collecting sizes from PowerShell or the usage reports. Those reports leave out recycle bin contents and online archives, both of which are billable. If you size a backup budget from them alone, you will under-forecast. Our free PowerShell scripts for mailbox, archive and site sizes produce the measured figures these fields want.
The other thing the reports won't tell you: the bill follows your storage curve, not your headcount. A tenant with a decade of project archives sitting in SharePoint pays for all of it every month unless someone scopes the policy deliberately. If you run more than one tenant, that is easier to see side by side: the MSP portfolio view costs every client at once and adds your resale markup.
Price is also only half the decision. The gaps native backup doesn't close — Teams chat, retention past a year, no export — cost the same whatever this number says.
What we'd check next
We're building a version that connects to your tenant with read-only permissions and fills these fields in from real data — measured sizes, unprotected mailboxes, leaver accounts approaching deletion, and which sites are safe to leave out of scope.
See worked examples at 50, 300 and 1,000 seats
Frequently asked questions
How much does Microsoft 365 Backup cost?
Microsoft 365 Backup is charged at $0.15 per GB of protected content per month. For a typical 300-seat tenant the calculator starts at about $2,738 a month for everything, or $1,440 with a scoped policy. Your actual bill depends on mailbox, archive and SharePoint sizes.
What counts as protected content?
Protected content includes primary mailboxes, online archives, OneDrive accounts, and SharePoint sites. Version history and recycle-bin content are also billable, which is why the usage reports most people check usually understate the total.
What is a scoped backup policy?
A scoped policy protects only the data you would realistically restore. In the default example it excludes online archives and stale SharePoint sites, which typically cuts the bill by 20-40% without removing anything business-critical.
Is Microsoft 365 Backup the same as OneDrive recycle bin?
No. The recycle bin, retention policies and version history are part of Microsoft 365, but they are not a true backup: they have time limits, no offline copy, and don't cover every loss scenario. See the limitations page for details.
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