AWS Savings Plans vs Reserved Instances: Which Saves More?

If you run steady compute on AWS, committing to it instead of paying on-demand is the single biggest lever on your bill — discounts reach up to roughly 72%. The question is how to commit: Savings Plans or Reserved Instances? For most teams in 2026, the answer is Savings Plans — but not always. Here's how to choose.

Short answer: Use a Compute Savings Plan for flexible, broad coverage of your steady-state compute. Consider Reserved Instances mainly for specific managed services (like RDS/ElastiCache/Redshift) or when you want capacity reservation.

The two commitment models

Savings Plans

You commit to a steady dollars-per-hour of usage for 1 or 3 years. In return you get discounted rates.

Compute Savings Plans — the most flexible. The discount automatically applies across EC2, Fargate, and Lambda, regardless of instance family, size, OS, tenancy, or Region. Up to ~66% off.
EC2 Instance Savings Plans — deeper discount (up to ~72%) but locked to a specific instance family in a Region.

Reserved Instances (RIs)

You commit to specific instance attributes (family, Region, sometimes size) for 1 or 3 years. Standard RIs give the deepest discount but little flexibility; Convertible RIs trade some discount for the ability to change attributes. RIs can also provide a capacity reservation in a specific AZ — something Savings Plans don't do.

Side by side

	Compute Savings Plan	Standard RI
Max discount	~66%	~72%
Flexibility	High (family, size, Region, Fargate, Lambda)	Low (locked attributes)
Capacity reservation	No	Optional (zonal RIs)
Covers Fargate/Lambda	Yes	No
Management overhead	Low	Higher (track expiries/usage)

How to decide

Find your steady-state baseline. Look at the floor of your compute usage over the last 30–90 days — the amount that's always running. Commit to that, not your peak. Burst above the baseline stays on-demand.
Default to a Compute Savings Plan for that baseline. The flexibility means you keep the discount even as you change instance types or shift to Fargate/Lambda — which most teams do over a 1–3 year horizon.
Use RIs for managed databases. Savings Plans don't cover RDS, ElastiCache, OpenSearch, or Redshift — those use Reserved Instances/Nodes. If you run steady databases, reserve them.
Reach for zonal RIs only when you need guaranteed capacity in a specific AZ (e.g., for failover headroom).
Prefer 1-year to start. Three-year terms discount more but assume you can predict usage that far out. Many teams ladder commitments instead.

The most common mistake

Over-committing. Teams commit to peak usage, then pay for a commitment they don't fully use. Commit conservatively to your baseline; you can always add more coverage later. Aim for high utilization of whatever you buy.

A right-sized Compute Savings Plan on a steady fleet typically trims 20–30% off compute spend with almost no operational change — just a purchase decision.

Not sure what your baseline is?

That's exactly what a cost review surfaces. The free AWS Cost Checkup reads your cost export and flags commitment gaps; or book a free consultation and we'll size it together.

Discount percentages are approximate and vary by term, payment option, and Region — confirm current numbers in the AWS Cost Management console.