By ec2calc.cloud maintainers · Published · Reviewed
Savings Plans vs Reserved Instances
Both offer significant discounts over On-Demand pricing, but they work very differently. Here's how to choose the right one.
TL;DR
Savings Plans
Commit to a dollar amount per hour. Flexible — applies across instance types, sizes, regions, and even services like Fargate/Lambda.
Reserved Instances
Commit to a specific instance type in a specific region. Less flexible but offers capacity reservation and marketplace resale.
Side-by-Side Comparison
| Feature | Savings Plans | Reserved Instances |
|---|---|---|
| Commitment | Dollar amount per hour (e.g. $10/hr) | Specific instance type in a specific region |
| Flexibility | Can change instance family, size, OS, region (Compute SP) | Locked to instance type, OS, and region |
| Max Discount | Up to ~66% (Compute SP) / ~72% (EC2 Instance SP) | Up to ~72% (Standard RI) / ~66% (Convertible RI) |
| Term Options | 1 year or 3 years | 1 year or 3 years |
| Payment Options | No Upfront, Partial Upfront, All Upfront | No Upfront, Partial Upfront, All Upfront |
| Applies To | EC2, Fargate, Lambda (Compute SP) | EC2 only |
| Marketplace Resale | ❌ Cannot sell unused commitment | ✅ Can sell Standard RIs on RI Marketplace |
| Size Flexibility | ✅ Automatic across sizes in same family | ✅ Linux/Unix Standard RIs in same family (regional) |
| Capacity Reservation | ❌ No capacity guarantee | ✅ Zonal RIs reserve capacity |
Savings Plan Types
Compute Savings Plans
Most flexible — any instance family, size, region, OS, tenancy
Best for: Teams that frequently change instance types or use multiple services (EC2 + Fargate + Lambda)
EC2 Instance Savings Plans
Locked to instance family & region, flexible on size, OS, tenancy
Best for: Stable workloads where you know the instance family and region but may change sizes
Reserved Instance Types
Standard Reserved Instances
Locked to instance type, OS, region. Can sell on Marketplace.
Best for: Predictable, steady-state workloads that won't change. Want resale option.
Convertible Reserved Instances
Can exchange for different instance type, OS, or tenancy (equal or greater value)
Best for: Long-term commitment but want ability to upgrade to newer generations
When to Use What
Frequently changing instance types
→ Compute Savings Plan
Maximum flexibility across families, regions, and services.
Stable workload, known family & region
→ EC2 Instance Savings Plan
Best discount with some flexibility on size and OS.
Guaranteed capacity needed
→ Zonal Reserved Instance
Only option that reserves actual capacity in an AZ.
May need to resell unused commitment
→ Standard Reserved Instance
Can be listed on the RI Marketplace.
Using Fargate or Lambda too
→ Compute Savings Plan
Covers EC2, Fargate, and Lambda under one commitment.
Want to upgrade to future generations
→ Convertible RI or Savings Plan
Both allow moving to newer instance types over time.
💡 When Reserved Instances still make sense
AWS recommends Savings Plans for most new commitments due to their flexibility. However, Reserved Instances remain the better choice when you need capacity reservation (zonal RIs guarantee capacity in a specific AZ) or want the option to resell unused commitment on the AWS Reserved Instance Marketplace — neither of which Savings Plans support.
See the savings in action
Our calculator shows On-Demand, Reserved Instances (1-year & 3-year), Savings Plans, and Spot prices side by side — with No Upfront, Partial Upfront, and All Upfront breakdowns for every instance type.
Open CalculatorA reproducible cost example
The recorded Linux/shared-tenancy on-demand quote for t3.micro in us-east-1 was $0.0104/hour, observed . At 730 hours, compute is $7.59/month. This dated example excludes storage, transfer, taxes and CPU credits; it is not a current price guarantee.
For an illustrative effective commitment rate of $0.0070/hour, including amortized upfront cost, break-even utilization is $0.0070 ÷ $0.0104 = 67.3%. This hypothetical commitment rate is not an AWS offer; unused commitment still costs money.
Sources and calculation assumptions
AWS features and rates can change. Follow the official references for service details and use the calculator for the selected instance and region. Price differences do not measure application performance.
Our data sources, cache policy and pricing formulas · Browse EC2 specifications and quotes