This calculator gives estimates for education and planning. It is not investment, tax or legal advice; for decisions about your own situation, talk to a qualified financial professional.
How cloud storage is billed
Object storage and cloud backup services charge mainly for three things:
- Storage: a price per gigabyte per month for the data you keep.
- Egress: a price per gigabyte for data downloaded out of the provider’s network.
- Requests: a small fee per thousand reads and writes, usually negligible for backups.
This calculator handles the first two, with monthly growth of your data.
The formulas
With S GB stored, a storage price p, growth g per month and n months, the storage paid over the period is a geometric series: S × p × ((1 + g)^n − 1) ÷ g. Egress adds E × e × n for E GB downloaded each month at a price e.
Example
1,000 GB at $0.023 per GB-month (a standard object storage tier) plus 100 GB of egress at $0.09 costs $32 the first month. With 5% growth per month, the data reaches about 1,710 GB after a year and the total for 12 months is about $474, or $39.51 a month on average.
| Tier or service type | Typical storage price per GB-month |
|---|---|
| Hot object storage (big three clouds) | $0.020 to $0.026 |
| Budget object storage | $0.006 to $0.007 |
| Infrequent access | about $0.0125 |
| Archive (retrieval takes hours) | $0.001 to $0.004 |
Check the current price list of your provider: rates change and depend on the region.
Cutting the bill
- Move data you rarely read to infrequent-access or archive tiers with lifecycle rules, but watch their retrieval fees and minimum storage durations.
- Compress and deduplicate backups before uploading.
- Egress often dominates for media delivery: a CDN or a provider with free egress can halve the bill.
- Delete old versions and incomplete multipart uploads, which are billed like normal data.
Cloud or a local NAS?
Over three to five years, a NAS can be cheaper for large volumes, but it needs a second copy off-site anyway. The 3-2-1 rule (three copies, two media, one off-site) often combines both.