DynamoDB On-Demand vs Provisioned Capacity: Break-Even Utilization
When provisioned capacity beats paying per request
Rates and break-even
Standard table class, in US East (N. Virginia). Break-even is the average utilization of provisioned capacity at which both modes cost the same.
| Operation | On-demand | Provisioned | Break-even utilization |
|---|---|---|---|
| WritesPer 1 KB write | $0.625 per million | $0.00065 per WCU-hour | 29% |
| ReadsPer 4 KB strongly consistent read | $0.125 per million | $0.00013 per RCU-hour | 29% |
Monthly cost for 100 provisioned units at different utilization
100 write capacity units and 100 read capacity units, running 730 hours a month. "Busy" is the share of provisioned capacity actually used; on-demand is billed on that traffic. The cheaper mode is highlighted.
| Utilization | Writes, on-demand | Writes, provisioned | Reads, on-demand | Reads, provisioned |
|---|---|---|---|---|
| 10% busy | $16.43Lowest | $47.45 | $3.29Lowest | $9.49 |
| 25% busy | $41.06Lowest | $47.45 | $8.21Lowest | $9.49 |
| 50% busy | $82.13 | $47.45Lowest | $16.43 | $9.49Lowest |
| 75% busy | $123.19 | $47.45Lowest | $24.64 | $9.49Lowest |
| 100% busy | $164.25 | $47.45Lowest | $32.85 | $9.49Lowest |
Which one to pick
Each recommendation links to the page for that option.
What to watch for
Gaps and gotchas that the price table does not show.
The break-even assumes perfect sizing
The 29% figure holds only if provisioned capacity matches the load. Real tables keep headroom for peaks and autoscaling reacts with a delay, so average utilization needs to sit comfortably above the break-even before provisioned wins in practice.
Reads and writes break even at the same point
Both modes bill in the same request units, and reads and writes are priced in the same ratio, so each breaks even at 29%. Item size, transactions and eventually consistent reads change how many units a request uses, not where the line sits.
You can switch modes, but not constantly
A table can switch between on-demand and provisioned once every 24 hours, so you can start on-demand and move to provisioned when traffic settles.
Storage, indexes and replication are separate
Neither mode changes storage at $0.25 per GB-month. Global secondary indexes consume capacity of their own in either mode.
Reserved capacity is not in the dataset
Provisioned tables can buy reserved capacity for a further discount. That rate is not in the processed data, so the table above uses standard provisioned prices.