Azure Managed Disk Calculator
Find which disk SKU your data lands in, how much you are paying for empty space, and how many gigabytes you would have to delete to drop a SKU. The boundary behaviour is what makes Azure disks different from EBS.
The Azure-specific waste
This is the difference from EBS and it catches people moving between the two. On AWS you pay per GB provisioned, so waste is gradual. On Azure a disk 5% over a SKU boundary costs exactly the same as one 95% over it — which means the cheapest fix is frequently deleting a few tens of gigabytes rather than changing tier at all.
Standard SSD would be cheaper
What this model assumes
- Azure bills disks by SKU, not by usage. A P30 costs the same holding 1 GB as holding its full 1,024 GiB, and a 600 GiB requirement is billed as a P30 because P20 stops at 512. That boundary behaviour is the whole model.
- Performance comes with the SKU. Premium SSD IOPS and throughput scale with size, so a bigger disk is also a faster one — sometimes the size is the performance requirement rather than a capacity one, and shrinking it is not free.
- LRS redundancy. ZRS and GRS cost more; the tier comparison shape survives, the absolute numbers do not.
- Not included: transaction charges, snapshots, Premium SSD v2 or Ultra Disk — both of which price capacity, IOPS and throughput separately and would need their own model.
Generated from the Azure Retail Prices API on 4 Aug 2026 for region eastus, LRS redundancy. Machine-generated rather than hand-transcribed — the date above is when the script ran. ZRS and GRS cost more.
Frequently asked questions
How is Azure managed disk pricing calculated?
By SKU, not by the space you use. A P30 costs the same holding one gigabyte as holding its full 1,024 GiB, and Azure bills the smallest SKU that fits your requirement. A 600 GiB disk is billed as a P30 because the SKU below it, P20, stops at 512.
Why is my Azure disk bill higher than the data on it?
Because you pay for the SKU rather than the contents. If your data sits just above a SKU boundary you are paying for the whole next tier — and a disk 5% over a boundary costs exactly as much as one 95% over it. This is the main structural difference from AWS EBS, which bills per GB provisioned.
Should I use Premium SSD or Standard SSD on Azure?
Standard SSD is substantially cheaper and gives 500 IOPS and 60 MB/s regardless of size. Premium SSD scales IOPS and throughput with the SKU. For application and log disks Standard is usually fine; for a database it usually is not. Note that on Premium, size and performance are the same dial — shrinking a disk to save money also slows it down.
How do I reduce Azure disk costs?
In order: delete enough data to drop a SKU (often only a few tens of gigabytes, and it costs nothing); move non-latency-sensitive disks from Premium to Standard SSD; delete unattached disks, which keep billing at full rate; and check snapshot retention, which is charged separately.
Does an Azure disk cost anything when the VM is stopped?
Yes, in full. Deallocating a VM stops the compute charge and leaves every attached managed disk billing at its normal SKU rate — the same trap as EBS on AWS.
Finding the disks is harder than pricing them.
Finitizer inventories every managed disk across every subscription, shows real used space against the SKU billed, and finds the unattached disks nobody remembers creating.