Is your commitment the right size?
Pick a usage profile, set what you commit to, and see what is used, what sits idle and the level that costs least. The same check works on Savings Plans, reserved instances and committed use discounts.
01A week of usage
On-demand value per hour, USDUsage over one week, from $59 to $223 an hour. Your commitment: $120 an hour. Lowest-cost level: $64 an hour.
$19,136 a month of commitment goes unused. At $64 an hour, the bill drops by $14,970 a month.
- Monthly cost now
- $91,669
- At the lowest-cost level, $64 an hour
- $76,700
- Everything on demand
- $87,600
With a 24% discount, one more dollar of commitment pays when it is used more than 76% of the hours. On this week, the level reached in 76% of the hours is $64 an hour.
Above that level, each extra dollar sits idle too often to pay for itself. Below it, you pay on-demand prices for hours you could have covered. Your provider's utilisation and coverage reports give the same two figures on your real usage.
Read: Savings Plans vs Reserved InstancesOne week of synthetic usage, repeated over the month. Discounts are those of a Compute Savings Plan on an m7i.large in EU (Paris), AWS list prices; they vary by service, region and family.
How this is calculated
A commitment is counted in on-demand value: each dollar an hour of commitment covers a dollar of usage every hour and is paid at the discounted rate, used or not. Usage above it is paid on demand. The lowest-cost level is found by trying every level on the week.
Discounts
| Term and payment | Rate an hour | Off on demand |
|---|---|---|
| 1 year No Upfront Compute Savings Plan | $0.08919 | 24% |
| 1 year All Upfront Compute Savings Plan | $0.08324 | 29% |
| 3 year No Upfront Compute Savings Plan | $0.06179 | 47% |
| 3 year All Upfront Compute Savings Plan | $0.05607 | 52% |
Against $0.1176 an hour on demand for an m7i.large, Linux, in EU (Paris). Sources: the AWS Price List for Amazon EC2 and for Compute Savings Plans (offer files of November 7, 2026, read on November 9, 2026), and Savings Plans types. The EC2 article prices the same plans.
The usage and the month
- Steady SaaS: Within about 10% of the average every hour, a little higher in the afternoon.
- Office hours: About 1.8 times the average from 8:00 to 20:00 on weekdays, about half of it nights and weekends.
- Nightly batch: About 2.4 times the average from midnight to 6:00, about half of it the rest of the day.
- Spiky: A flat base, with about one hour in eight at two to three times it.
- Each profile is one synthetic week, scaled to the average you set and repeated over a month of 730 hours.
- “About right” means within 5% of the lowest-cost level.
- An upfront payment is counted at its hourly rate: the cost of paying early is left out.
The audit puts your own figures on it.
Free, 48 hours, from your billing exports and with your negotiated discounts. I'm paid 20% of the savings measured on your bill, for 12 months, and nothing if the bill does not go down.