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M365Email & Communication

How to Check Your Microsoft 365 Data Volume

Review Exchange mailbox, OneDrive, and SharePoint storage from the Microsoft 365 admin center.

Verified against official documentationLast checked October 16, 2026
This is a read-only preliminary check.

Do not export, upload, or send business records. Write down only the approximate storage figures you see.

What this platform may hold

Know what you are measuring.

  • Outlook mailboxes
  • OneDrive files
  • SharePoint sites
  • Teams-connected content
Permissions required

Supported reporting role

Microsoft permits several reporting and service-admin roles, including Reports Reader, Usage Summary Reports Reader, Exchange Administrator, and SharePoint Administrator. Use the least-privileged role that fits.

Start in the source system

Go to admin.microsoft.com and sign in.

Use the authorized role listed above, then keep this Steady Data guide open beside the portal and follow the visual steps below.

Open Microsoft 365 admin center Opens the source system in a new tab. Never share your password with Steady Data.
Official vendor instructions

Want the vendor's full documentation? Open any source below without losing this guide.

Each link opens in a new tab.
Check your data volume

Follow these steps.

Product screens can change. Follow the verified labels and use the linked vendor sources if your layout differs.

01

Open the admin center

Go to admin.microsoft.com and sign in with an account that has a supported reporting or service-admin role.

Microsoft 365 admin centerSign in
If Reports is unavailable, ask your Microsoft 365 administrator to verify your role.
Microsoft 365 · original navigation mapStep 1
Open the admin centerExample layout
Search settings and reports
Overview
Admin accountChoose this
Users and access
Original Steady Data illustration—not a product screenshot. Labels and navigation are based on the official vendor documentation linked below.
02

Open Usage reports

In the navigation, select Reports, then Usage. If Reports is hidden, select Show all first.

ReportsUsage
Reports commonly take 24–72 hours to reflect new activity or changes.
Microsoft 365 · original navigation mapStep 2
Open Usage reportsExample layout
Search settings and reports
Overview
UsageChoose this
Users and access
Original Steady Data illustration—not a product screenshot. Labels and navigation are based on the official vendor documentation linked below.
03

Record Exchange mailbox storage

Open Exchange, choose Email activity, select View More, then Exchange > Mailbox usage. Record storage used and quota.

ExchangeMailbox usage
The storage chart excludes archive mailboxes, so record archive scope separately when relevant.
Microsoft 365 · original navigation mapStep 3
Record Exchange mailbox storageExample layout
Record this figureStorage overviewYour used storage
UsedTotal limit
Original Steady Data illustration—not a product screenshot. Labels and navigation are based on the official vendor documentation linked below.
04

Record OneDrive and SharePoint

Open OneDrive and select Usage. Then open SharePoint and select Storage. Record the used figure for both services.

UsageOneDrive / SharePoint
The SharePoint Storage report typically refreshes every 48–72 hours.
Microsoft 365 · original navigation mapStep 4
Record OneDrive and SharePointExample layout
EmailMailbox usage
FilesStorage used
SitesTotal usage
Write down each service separately
Original Steady Data illustration—not a product screenshot. Labels and navigation are based on the official vendor documentation linked below.
Used vs. limit

Record what is used—not just what is available.

Microsoft reports storage by service. Mailbox usage, OneDrive usage, and SharePoint storage use different pools or quotas, so record each used figure instead of treating one screen as a universal tenant total.

Historical coverage

Storage size does not equal record age.

Usage reports can show 7-, 30-, 90-, or 180-day activity and storage trends. Those windows do not prove the age of the oldest retained content. Review retention policies and oldest permitted records separately.

Troubleshooting

Common reasons your screen may differ.

Reports is missing+

Select Show all. If it remains unavailable, your account likely needs a supported reporting role.

Names or sites are hidden+

Microsoft can de-identify user, group, and site details. An administrator controls that report setting.

The totals do not match+

Exchange, OneDrive, and SharePoint measure different services and quotas. Keep each figure labeled.

Later-stage process

Prepare or export data only after authorization.

Microsoft Purview eDiscovery export

For later-stage authorized collection, Microsoft Purview eDiscovery can export selected mailbox, OneDrive, and SharePoint content after a case and search are configured.

Permissions and safeguardsExport requires appropriate eDiscovery permissions and qualifying Microsoft 365 licensing. Confirm scope, legal authority, retention, and privacy controls first.
1. Microsoft Purview2. eDiscovery case3. Search4. Export

Typical output: Mailbox items as PST or messages; SharePoint and OneDrive files in native formats.

Official sources

Verify the latest vendor guidance.

These official pages were used to verify this guide. Vendor interfaces and permissions can change.