Rightsize
Learn how Rightsize finds cost and performance improvements for your cloud resources.
Rightsize finds cloud resources that cost more than they need to, or that do not have enough capacity for their workload. It recommends a better size for each one, based on how you actually use it.
How Rightsizing Works
Rightsize looks at a resource's actual usage over a lookback window. It calculates a high percentile of that usage, so one quiet week does not skew the recommendation. It adds a safety margin on top of that peak, then finds the smallest size that still fits.
This calculation is deterministic. The same usage data always produces the same recommendation.
Rightsize re-analyzes every account every night. Saving a change in Rightsize settings also triggers an immediate recompute.
What Rightsize Covers
Use the service selector at the top of the page to switch between resource types. Each service has its own cost chart, table, and available-savings figure.
AWS accounts: EC2, EBS, ECS, and Auto Scaling groups.
GCP accounts: Compute Engine.
Rightsize does not size GPU-accelerated instances or Spot instances. Their real usage does not show up correctly in CPU or memory metrics alone.
Monitoring Access
Rightsize needs to read utilization metrics before it can size anything.
AWS - grant access for your org, and separately for any linked account you want Rightsize to analyze.
GCP - grant access for every project you want Rightsize to analyze.
If access is missing for an account or project, Rightsize excludes its resources from its findings. A banner on the page tells you how many resources are excluded, and guides you through granting access.
Using the Rightsize Page
The page shows a cost chart, summary metrics for that service, and a table of individual resource recommendations. To see findings for each service Rightsize supports, switch to a different service using the service selector at the top of the page.
Cost chart - shows the selected service's spend. Switch between Amortized and Unblended to change the chart's cost basis.
Summary metrics - Available Savings, the total monthly savings across this service's resources, plus counts of resources that are Idle, Over provisioned, or Under provisioned, and the share of resources that are Tagged versus Untagged.
Filters - narrow the table by Type, Region, Reason, or Cohort. Turn on Non-Optimized to hide resources that are already right-sized. By default, the table also hides resources with no recommendation; select Insufficient data in the filters to bring them back.
Tag filters - use the Filter button to filter by tag key and value.
Search - find a specific resource by name.
Rightsize Settings
Open Settings (the gear icon) to control how Rightsize analyzes your account.
Reading utilization metrics has a small cost, billed by your cloud provider. The exact amount depends on the settings you choose below, and the Spend guardrail settings cap it.
Profile - choose Conservative, Balanced, or Aggressive. Balanced is the default. Conservative uses wide safety margins and only recommends clear wins. Aggressive uses the tightest margins and surfaces the most savings.
Never touch - exclude specific resources, or anything carrying a tag you choose. Excluding a member of a group excludes the whole group.
Spend guardrail - set an analysis cost floor (resources cheaper than this are skipped) and a monthly cap on what Rightsize spends reading metrics.
Advanced - manually set any individual value behind your chosen profile, grouped as:
Coverage & cadence - how much of your spend to cover, and how often to re-check a resource.
Sizing - the lookback window, the usage percentile, and the CPU and memory headroom.
Savings floors - the minimum savings, in dollars or as a share of the resource's cost, worth recommending.
You need write permission on Rightsize to change these settings. See IAM Permissions or ask your org admin if Settings does not let you edit.
Understanding Each Finding
Every analyzed resource gets a finding: a state that summarizes Rightsize's verdict, and one or more reasons behind it. Use these to see, at a glance, what Rightsize concluded about a resource and why, before you act on it.
Finding States
Each finding has one state:
Over provisioned
The resource is bigger than its usage needs. A smaller option is recommended.
Under provisioned
Usage is close to the limit of the current size. A bigger option is recommended.
Optimized
The current size is already the right one.
Not optimized
A cost improvement exists that is not a size change. For example, a volume paying for provisioned performance it does not use.
Idle
The resource shows no meaningful activity. It is a candidate to stop or remove.
Insufficient data
Rightsize could not measure the resource with confidence, so it did not guess.
Not analyzed
The resource is deliberately out of scope, for example Spot capacity.
Finding Reasons
Each finding comes with one or more reasons: which metric drove it, why a recommendation was capped, or why none could be made. Check these before you act on a recommendation, to understand what it is actually based on.
The table's Reasons column shows a count of how many reasons apply to a resource. Open the Reason filter dropdown to see the labels, or click a row's AI Suggestion button to see them as Findings chips on that resource's panel.
Sizing dimensions - which metric drove the finding:
CPU Overprovisioned / Underprovisioned
Memory Overprovisioned / Underprovisioned
Group Overprovisioned / Underprovisioned (Auto Scaling groups)
Network Bandwidth / PPS (Packets Per Second) Overprovisioned
Volume IOPS (Input/Output Operations Per Second) / Throughput Overprovisioned - an active volume paying for performance it does not use
Cheaper volume type available
Why a recommendation is capped or withheld:
Limited by peak load
A smaller size passed the average-usage test, but the actual peak in the window would overload it.
Limited by network throughput
The smallest size Rightsize will recommend still carries the observed network peak.
Limited by storage throughput
The same idea, for observed storage traffic. This checks throughput evidence only, not IOPS safety.
Limited by missing memory data / No memory metrics
No memory agent is reporting data, so the recommendation is bounded by CPU alone.
Volatile usage
Usage swings too much for a confident recommendation at full depth.
Burst credits exhausted
A burstable instance is running past its baseline. This points toward upsizing, not downsizing.
Burst capacity verified
A downsize was only proposed after confirming the volume's burst headroom covers its spikes.
Monitoring access denied
Rightsize does not have the monitoring grant needed to read this resource's utilization metrics. See Monitoring Access, above.
Region restricted
The resource sits in an isolated AWS partition that North's commercial connection cannot reach, such as AWS GovCloud or a China region. Granting more access does not change this, because the partition is unreachable rather than unauthorized. Rightsize refuses these resources before it reads any metrics, so they cost you nothing to skip.
Extended memory pricing unavailable
The resource carries more memory than its instance family's standard allowance, and Rightsize has no rate for that configuration.
Linked account missing
Rightsize could not identify which linked account in your AWS Organization owns this resource, so it could not size it.
No observed activity
Every metric reading came back empty for the full lookback window. The resource showed no activity for Rightsize to measure.
Other labels you may see:
Covered by a commitment
Usage is mostly covered by a Reserved Instance, Savings Plan, or Committed Use Discount. Rightsize still analyzes it. Savings are calculated on the on-demand rate and take effect at the commitment's renewal.
Commitment limits sizing to this family
The covering commitment restricts sizing to the resource's current family, so recommendations stay within it.
Review Reserved Instance coverage before resizing
Resizing this resource would change what its Reserved Instance covers.
Unattached
A volume not attached to anything.
Review before deleting
Rightsize recommends removing this resource.
Deferred to a later run / Carried from the previous run
The resource is queued for a later analysis, or its last verdict was reused because nothing changed enough to re-check it.
Why a Resource Has No Recommendation
Clicking a row with no recommendation opens a panel naming the reason when it is something you can fix:
Grant monitoring access to size this resource. See Monitoring Access, above.
Tag this task's service to get its utilization. This task carries no service tag, so Rightsize cannot attribute its usage to it.
Spot capacity isn't right-sized. Spot capacity is reclaimed and priced on different terms, so Rightsize leaves it as it is.
GPU instances aren't right-sized. Rightsize sizes on CPU, memory, and network. The accelerators that decide a GPU machine's size are not among them.
Other cases show a general note that no recommendation exists for that resource. A resource marked Region restricted is one of them, because no action on your side makes it analyzable.
Limitations
Rightsize only recommends. It never changes, resizes, or stops a resource on your behalf.
GPU-accelerated and Spot instances are not sized.
Resources in isolated AWS partitions, such as AWS GovCloud and China regions, are not analyzed. North's commercial connection cannot reach those partitions.
An AWS linked account or a GCP project without a monitoring grant is excluded from analysis until you grant access to it.
Settings apply to your whole account today, not to individual member accounts within it.
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