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What is DynamoDB Reserved Capacity?
AWS calls this pricing option DynamoDB reserved provisioned capacity.You commit to a minimum amount of provisioned read or write capacity for a fixed term. In return, you pay a partial upfront fee plus a discounted hourly rate.
According to the AWS DynamoDB Reserved Capacity documentation, it applies to provisioned DynamoDB Standard capacity.
It does not cover:
on-demand capacity
DynamoDB Standard-IA
replicated write capacity units (rWCUs)
For the underlying capacity choice, see our DynamoDB On-Demand vs Provisioned guide.
DynamoDB 1-year vs 3-year Reserved Capacity
| 1-year | 3-year | |
|---|---|---|
| AWS-published maximum savings | Up to 54% | Up to 77% |
| Term | 12 months | 36 months |
| Availability | All supported Regions | Selected Regions |
| Payment | Partial upfront + hourly | Partial upfront + hourly |
| Commitment exposure | Lower | Higher |
| Best suited for | Stable but evolving usage | Highly predictable long-term usage |
Important: The one-year option is more flexible only because it ends sooner. Both terms are non-cancellable and non-transferable.
How much can 1-year vs 3-year Reserved Capacity save?
Start with the standard provisioned rate, then compare it with the effective reserved rate.AWS currently uses $0.00065 per WCU-hour for provisioned DynamoDB Standard capacity in US East (N. Virginia) in its pricing examples.
For 100 WCUs running continuously:
| Standard | 1-year max discount | 3-year max discount | |
|---|---|---|---|
| Published discount | 0% | Up to 54% | Up to 77% |
| Illustrative annual equivalent at maximum published discount | $569.40 | About $261.92 | About $130.96 |
| Commitment | None | 1 year | 3 years |
When does a 1-year reservation make sense?
A one-year commitment is usually easier to justify when usage is stable but the environment may still change.Consider one year when:
the application is still growing
provisioned capacity changes over time
architecture or Region changes are possible
a migration may happen within a few years
you want commitment savings without 36 months of exposure
When does a 3-year reservation make sense?
A three-year term is more suitable when the capacity floor is highly durable.Typical signals include:
the application is mature
DynamoDB is expected to remain the database
baseline RCUs and WCUs have been stable
major Region changes are unlikely
the workload is unlikely to be retired or redesigned
Why utilization matters more than the headline discount
DynamoDB Reserved Capacity applies to provisioned throughput capacity, not directly to the number of requests your application sends.Suppose you reserve 1,000 WCUs but later provision only 700 WCUs.
A useful planning metric is:
700 ÷ 1,000 = 70%
AWS’s DynamoDB capacity optimization guidance recommends considering workload predictability and provisioned-capacity utilization when choosing a capacity model.
How Auto Scaling changes the decision
The commitment applies to provisioned throughput, not directly to actual request volume.DynamoDB Auto Scaling can raise or lower the RCUs and WCUs provisioned for your table as traffic changes.
If Auto Scaling regularly reduces capacity below your reserved amount, some of your Reserved Capacity may have no matching provisioned capacity to cover.
That is why a safer commitment target is usually the persistent capacity floor, not the daytime peak or monthly average.
Can Reserved Capacity work across tables and accounts?
Reserved Capacity is not tied to an individual table.AWS applies eligible capacity within the Region where the reservation was purchased.
With consolidated billing, Reserved Capacity is applied first to the purchasing account. Unused eligible capacity can then be shared with linked accounts under the payer account.
AWS explains this billing behavior in its DynamoDB Reserved Capacity pricing guidance.
Reserved Capacity remains Region-specific.
For multi-Region deployments, see our DynamoDB Global Tables pricing guide.
What happens if your workload changes?
This is the main financial risk.AWS states that DynamoDB Reserved Capacity cannot be:
cancelled
sold
transferred to another Region
transferred to another account
The better purchasing question is therefore not:
Which term has the biggest discount?
It is:
How much capacity am I confident will still exist at the end of the term?
Reserved Capacity vs Database Savings Plans
Database Savings Plans offer a more flexible one-year commitment model for some DynamoDB workloads.| Reserved Capacity | Database Savings Plans | |
|---|---|---|
| Term | 1 or 3 years | 1 year |
| Provisioned DynamoDB savings | Up to 77% | Up to 12% |
| On-demand DynamoDB savings | Not eligible | Up to 18% |
| Region flexibility | No | Yes, for eligible usage |
| Broader database flexibility | No | Yes |
If both discounts could apply to the same provisioned usage, Reserved Capacity is applied first. Remaining eligible usage can then receive Database Savings Plan benefits.
Compare Database Savings Plans first when:
your eligible database spend spans multiple Regions
you use several supported AWS database services
database modernization or migration is likely
flexibility matters more than maximizing the DynamoDB-specific discount
How to choose between 1 year and 3 years
1. Measure provisioned capacity
Review historical RCUs and WCUs across normal, peak, and quiet periods.2. Find the durable baseline
Identify capacity that remains provisioned consistently, not capacity that exists only during predictable peaks.3. Review Auto Scaling
Check how often provisioned capacity falls below the amount you are considering reserving.4. Account for planned changes
Include migrations, application retirement, redesigns, and Region changes.5. Stress-test the commitment
Model what happens if your baseline falls by 20% or 30%.6. Compare alternatives
Model one-year Reserved Capacity, three-year Reserved Capacity, regular provisioned pricing, and Database Savings Plans.7. Validate before purchasing
Check historical DynamoDB costs in AWS Cost Explorer, review existing commitment coverage, and compare your proposed quantity with the current Region-specific Reserved Capacity offering.If you are considering Database Savings Plans, also review AWS’s current Savings Plans recommendation and purchase-analysis tools before committing.
DynamoDB Reserved Capacity checklist
Before purchasing:Confirm provisioned capacity mode
Confirm DynamoDB Standard table class
Measure stable RCUs and WCUs
Review Auto Scaling history
Separate persistent baseline from peaks
Confirm the AWS Region
Check 3-year availability
Model a significant usage decline
Review existing Reserved Capacity and Database Savings Plan coverage
Validate current AWS pricing before purchase
How Usage.ai Fits Your DynamoDB Strategy
The difficult part is not finding the larger discount. It is deciding how much AWS usage is safe to commit long term.We analyze cloud usage and help identify stable eligible demand before commitments are purchased.
For eligible AWS workloads, our Flex Insured Commitments can help teams access up to 57% savings associated with a three-year AWS commitment while reducing long-term commitment exposure.
If an eligible Flex Commitment costs more than equivalent On-Demand usage, we provide cashback protection to help cover the qualifying difference, subject to current program eligibility and terms.
For customers on a savings-based model, our fee may be calculated against realized savings generated through commitments covered by the applicable agreement.
Disclosure
We are a cloud cost optimization and commitment-management company. DynamoDB Reserved Capacity and Database Savings Plans are AWS products.AWS controls pricing, eligibility, Region availability, discounts, and billing mechanics. Our Flex Commitments are a separate service subject to current eligibility and program terms.
Frequently asked questions
How much can DynamoDB Reserved Capacity save?
AWS currently publishes savings of up to 54% for a one-year term and up to 77% for a three-year term. Actual savings depend on Region, pricing, capacity purchased, and utilization.
Is 1-year or 3-year DynamoDB Reserved Capacity better?
One year has a shorter commitment period. Three years provides a larger maximum discount. The right term depends on how confidently you can forecast stable provisioned capacity.
Can DynamoDB Reserved Capacity be cancelled?
No. AWS states that Reserved Capacity cannot be cancelled, sold, or transferred to another Region or account.
Does Reserved Capacity work with DynamoDB on-demand?
No. Reserved Capacity applies to eligible provisioned DynamoDB Standard capacity. Database Savings Plans can instead provide discounts on eligible DynamoDB on-demand usage.
Can Reserved Capacity cover DynamoDB Global Tables?
It can cover eligible standard provisioned RCUs and WCUs, but AWS does not allow Reserved Capacity purchases for replicated WCUs. Reserved Capacity is also Region-specific.
