Microsoft 365 backup cost calculator: storage and published prices compared

Enter your users and how much mail, OneDrive and SharePoint data each one has. The calculator estimates the backup storage you need now and over three years, then prices it with Microsoft 365 Backup's pay-as-you-go rate and every vendor that publishes a list price. Vendors that hide their prices are shown as "price on request", never guessed.

Prices last checked: 16 October 2026, each with its source. The calculator runs in your browser and sends nothing anywhere. No links on this page pay us anything.

Disclosure: the author works in the data protection industry. This tool is independent: no vendor paid for it, reviewed it or supplied data for it, and it uses only publicly available information and list prices.

How to read the result

• Protected data is what you back up today: users x (mailbox + OneDrive + SharePoint per user).
• Backup storage adds the old versions and deleted items the backup keeps for your retention period. It is what Microsoft 365 Backup bills on, and what you pay a cloud provider for if you run the backup yourself.
• The cost table has three kinds of row. Per-GB pricing (Microsoft) grows with your data. Per-user pricing stays flat while the user count does, but some plans include only a fixed amount of storage per user, flagged in the row. Self-hosted software and the self-managed storage row need both a licence and storage, so add them together.
• "Price on request" means the vendor publishes no list price. We do not estimate one.

How is Microsoft 365 backup storage and cost calculated?

1. Protected data = users x (mailbox GB + OneDrive GB + SharePoint and Teams GB per user). Teams has no store of its own: channel files sit in SharePoint, files shared in chats in OneDrive, and chat messages in hidden folders in mailboxes.
2. Backup storage = protected data x (1 + share changed or deleted per year x years kept). A backup keeps every version and deleted item until its retention expires, so a longer retention holds more of them.
3. Growth. Year n multiplies both figures by (1 + growth)^n. The user count stays fixed, so per-user costs do not grow.
4. Microsoft 365 Backup = backup storage in GB x $0.15 a month. Microsoft bills the live size of protected mailboxes (with online archives), OneDrive accounts and SharePoint sites, plus deleted and versioned items held in the backup, with no separate Azure storage charge.
5. Per-user vendors = users (or the vendor's minimum, rounded up to its pack size) x price per user. Annual prices are divided by 12 for the monthly column. Volume tiers apply to all users once you cross a band.
6. Self-managed storage = backup storage in TB x the object storage list price you pick, from the same price table as our backup storage calculator.

Worked example: 250 users

A 250-person company has 10 GB of mail, 25 GB of OneDrive and 10 GB of SharePoint and Teams files per user. It keeps backups for one year, and 20 percent of its data is changed or deleted each year. These are the calculator's defaults.

• Protected data: 250 x (10 + 25 + 10) GB = 11,250 GB, or 11.25 TB.
• Backup storage: 11,250 GB x (1 + 0.2 x 1) = 13,500 GB, or 13.5 TB. At 20 percent growth that becomes 23.3 TB in year 3.
• Microsoft 365 Backup: 13,500 GB x $0.15 = $2,025 a month, $24,300 a year, rising to about $42,000 a year by year 3 as the data grows.
• Veeam Data Cloud for Microsoft 365 (Foundation): 250 users fall in the 51-250 band at $3.15 a month, so 250 x $3.15 = $787.50 a month, $9,450 a year, with unlimited storage. It stays at that figure while the user count does.
• Self-managed backup to Amazon S3 Standard-IA: 13.5 TB x $12.50 = $168.75 a month for storage, plus the backup software licence (for example CubeBackup at $5 per user per year, $104 a month for 250 users) and your own time to run it.

The general rule: per-GB pricing wins for light users and loses for heavy ones. The break-even is the per-user price divided by $0.15. At $3.15 a user a month, Microsoft's rate is cheaper only while each user has less than 21 GB held in backup.

Assumptions and published prices

Every default and price comes from the table below, checked on . Prices are the vendor's own published list price, from its website or its own Azure Marketplace listing (US market). Quotes are the vendor's words.

What are the calculator's limitations?

• List prices only. Resellers, managed service providers, enterprise agreements and multi-year terms usually change the price, and some "starting at" prices rise with features.
• Not like for like. Products differ in what they back up (Teams chats, Planner, Entra ID), how often, where the copy lives (inside or outside Microsoft's cloud), restore speed and retention. Compare features before price.
• Change rate is an assumption. Measure it: Microsoft suggests the size of the second-stage recycle bin as a rough guide to three months of churn.
• Currencies are not converted. Most prices are in US dollars; Acronis is shown in pounds from its UK store.
• Microsoft's recovery window can be set to 3 months, 6 months, 1 year or 2 years. Longer retention needs another product.

Frequently asked questions

How much does Microsoft 365 Backup cost?

Microsoft's list price is $0.15 per GB per month of protected content, billed pay-as-you-go through an Azure subscription. The billed size includes protected mailboxes with their online archives, OneDrive accounts and SharePoint sites, plus deleted and versioned items held in the backup. There is no separate Azure storage charge and restores are free. 250 users with 45 GB each and a year of changes held come to about $2,025 a month.

Is per-GB or per-user Microsoft 365 backup cheaper?

It depends on data per user. Divide a per-user monthly price by Microsoft's $0.15 per GB to get the break-even: at $3.15 a user, Microsoft 365 Backup is cheaper below about 21 GB held per user and dearer above it. If your users hold more than that, a per-user plan with unlimited storage costs less at list price.

How much storage does a Microsoft 365 backup need?

Start with users x (mailbox + OneDrive + SharePoint data per user), then add the versions and deleted items kept for your retention period. With 45 GB per user, 20 percent of data changed or deleted a year and one year of retention, 250 users need about 13.5 TB.

Does Microsoft 365 Backup cover Teams?

Microsoft 365 Backup protects Exchange Online mailboxes, OneDrive accounts and SharePoint sites. Teams keeps channel files in SharePoint, files shared in chats in OneDrive and chat messages in hidden mailbox folders, so the files are covered when those sites and accounts are in a backup policy. Check Microsoft's documentation for how Teams messages can be restored before relying on it for them.

Why do some backup vendors show "price on request"?

Several vendors sell only through partners or sales teams and publish no list price, including Keepit, Spanning, Datto SaaS Protection, Cohesity and Veeam's self-managed Backup for Microsoft 365 software. Rubrik's Azure Marketplace plans contradict each other, so we treat it as price on request too. We never estimate a price a vendor has not published.

Is there a free Microsoft 365 backup calculator without a sign-up?

Yes, this one, which also compares vendors' published prices and adds growth. Microsoft also publishes a free Excel pricing calculator for its own Microsoft 365 Backup service, linked from its pricing documentation.

Sources

• Microsoft Learn: pricing model for Microsoft 365 Backup and Microsoft 365 Backup overview (recovery window, benchmark mailbox)
• Microsoft Learn: Exchange Online limits, OneDrive service description and SharePoint limits
• Microsoft Learn: where Teams stores chats and files
• Vendor prices: each row of the table above links to the vendor page or Azure Marketplace listing it was read from on 16 October 2026.

Related

• Backup storage calculator: retention, GFS and 3-2-1 copies
• The 3-2-1 backup rule, and how to actually do it in 2026

Changelog

• 16 October 2026: first release. Prices checked on 16 October 2026.