Sustained use discounts
Compute Engine offers sustained use discounts (SUDs) on resources thatare used for more than 25% of a billing month and are not receiving any otherdiscounts. Whenever you use an applicable resource for more than a fourth of abilling month, you automatically receive a discount for every incremental hourthat you continue to use that resource. The discount increases incrementallywith usage and you can get up to a 30% net discount off of the resource costfor virtual machine (VM) instances that run the entire month.
Limitations
Sustained use discounts have the following limitations:
OnlySelf-serve (or Online) Cloud Billing accountsare eligible for receiving SUDs.
SUDs don't apply to the resource usage that isalready covered by committeduse discounts (CUDs).
SUDs don't apply to VMs created using the App Engine (standard and flexible)environments and Dataflow. Only VMs created by Google Kubernetes Engineand Compute Engine are eligible for SUDs.
Sustained use discounts apply only to the machine series listed in theEligible resources and discount percentagessection.
Eligible resources and discount percentages
The following resources are eligible to receive sustained use discounts:
- The vCPUs and memory for general-purposeN1,N2, andN2D custom andpredefined machine types
- The vCPUs and memory for compute-optimizedC2 machine types
- The vCPUs and memory for memory-optimizedM1 andM2 machine types
- The vCPUs and memory forsole-tenant nodes
- The premium cost for sole-tenant nodes, even if the vCPUs andmemory in those nodes are covered by CUDs
- GPU types that are attached to N1 general-purposemachines. However, sustained use discounts don't apply to any GPUs that areavailable with the accelerator-optimized machines.
Compute Engine offers a maximum monthly SUD percentage of either 20%or 30% depending on the resource and machine types. The following table showsthe list of resources that are eligible for each SUD percentage:
| Maximum of 20% monthly SUDs | Maximum of 30% monthly SUDs |
|---|---|
|
|
How sustained use discounts work
Compute Engine automatically calculates and applies SUDsto resource usage within a Cloud Billing account, so there is no actionrequired on your part to enable these discounts.
Sustained use discount credits
You receive SUDs in the form of monthly credits. At the end of every month,for every eligible Compute Engine resource that you use, you receiveapplicable SUDs as credits based on the duration of time for which you used thatresource. Any credits that you receive for your SUDs have no cash value.Compute Engine uses these credits to offset your monthly resourceusage costs. You can't store or use these credits beyond the month in whichyou receive them.
You can view all your earned credits during a particular month inthe cost table report for your Cloud Billing account on theGoogle Cloud console. To learn more about credits and how to view them,see View and analyze your credits.
Sustained resource usage time
To calculates SUDs for your eligible resources, Compute Engine firstcalculates the total sustained resource usage time during a given month, for allthose resources. You then receive SUDs credits for each of those individualresources, based on their usage and maximum monthly SUD percentage.
You don't have to run your VMs continuously throughout the month for them toqualify for sustained resource usage time. Even if you stop your VMs for certaintime periods during the month, Compute Engine aggregates all theindividual usage times for each resource during that month. For every resource,Compute Engine also aggregates the individual usage times for all usagefrom that machine family and region.SeeExample scenario for sustained use discounts calculationfor a detailed example.
Caution: When you move a project to a new Cloud Billing account, thesustained resource usage time stops accruing for the old account and startsaccruing in the new account. Google Cloud doesn't carry forward your sustainedresource usage time and starts calculating the time from zero in your newaccount. As a result, your sustained resource usage time gets split and theresulting SUDS are calculated separately for each account. To ensure that youmaximize the SUDs for each account, Google Cloud recommends that you make anynecessary modifications to the Cloud Billing accounts of your projectsonly on the first day of a given month.Incremental usage levels
You receive applicable SUDs on incremental use of your resources. During a month,the discount percentage that you receive for your resources increases after youreach certain usage thresholds. These usage thresholds are set at 25%, 50%, 75%,and 100% of the month. If you use a resource for the full duration of the month,then the incremental discounts add up on that resource and you end upeffectively receiving the maximum monthly SUD percentage that is available forthat resource.
For example, consider a resource that has a maximum monthly SUD of 30%. If youuse the resource for 50% of the month, you get an effective SUD of 10%. If youuse it for 75% of the month, you get an effective SUD of 20%. If you use it for100% of the month, you get an effective SUD of 30%. You can also use theGoogle Cloud Pricing Calculator to estimate the SUDfor any arbitrary workload. This same process also applies to the resources forcustom machine types.
Your SUDs reset at the beginning of each month. To take advantage of the maximumavailable SUD for your resources, create your VM instances on the first day ofthe month and use them for the full duration of that month. If you don't useyour resources for the full month, Compute Engine automatically givesyou the best price by calculating the discount based on your usage levels.
Note: Sustained use discounts apply only to resource prices. All other chargesare applied on top of the discounted resource price. For example,premium images are charged anadditional fee on top of any sustained use discounted resource prices.Sustained use discounts per usage level for maximum 30% monthly discount
The following table shows the SUDs breakdown per usage level for the resourcesthat receive a maximum monthly discount of 30%. Each row provides informationabout the resource cost and discount percentage that you receive during thatusage level. To calculate your monthly SUDs, Compute Engine aggregatesyour discounts across the individual usage levels. In this example, the tableshows the data for an N1 machine type resource that has an on-demand price ofUS$0.0475 per hour.
| Sustained resource usage level | Cost with no discount (US$ per hour) | Discounted cost for the usage level (US$ per hour)* | Effective cost at the usage threshold (US$ per hour) | Overall SUD at the usage threshold |
|---|---|---|---|---|
| 0% to 25% of the month | 0.0475 | 0.0475 (100% of the on-demand price) | 0.0475 | 0% |
| 25% to 50% of the month | 0.0475 | 0.038 (80% of the on-demand price) | 0.04275 (average of the first two usage levels) | 10% |
| 50% to 75% of the month | 0.0475 | 0.0285 (60% of the on-demand price) | 0.038 (average of the first three usage levels) | 20% |
| 75% to 100% of the month | 0.0475 | 0.019 (40% of the on-demand price) | 0.03325 (average of all the usage levels) | 30% |
Sustained use discounts per usage level for maximum 20% monthly discount
The following table shows the SUDs breakdown per usage level for the resourcesthat receive a maximum monthly discount of 20%. Each row provides informationabout the resource cost and discount percentage that you receive during thatusage level. To calculate your monthly SUDs, Compute Engine aggregatesyour discounts across the individual usage levels. In this example, the tableshows the data for a C2 machine type resource that has an on-demand price ofUS$0.2088 per hour.
| Sustained resource usage level | Cost with no discount (US$ per hour) | Discounted cost for the usage level (US$ per hour)* | Effective cost at the usage threshold (US$ per hour) | Overall SUD at the usage threshold |
|---|---|---|---|---|
| 0% to 25% of the month | 0.2088 | 0.2088 (100% of the on-demand price) | 0.2088 | 0% |
| 25% to 50% of the month | 0.2088 | 0.1811 (86.78% of the on-demand price) | 0.19495 (average of the first two usage levels) | 6.6% |
| 50% to 75% of the month | 0.2088 | 0.1530 (73.3% of the on-demand price) | 0.180967 (average of the first three usage levels) | 13.3% |
| 75% to 100% of the month | 0.2088 | 0.1252 (60% of the on-demand price) | 0.167025 (average of all usage levels) | 20% |
The following graph shows an example scenario where your effective sustained usediscount increases with use, up to a maximum of 30% by the end of the month:
Example scenario for sustained use discounts calculation
Consider a scenario where you have two VMs or sole-tenant nodes in thesame region that have different machine types and run at different times of themonth. Compute Engine breaks down the number of vCPUs and amount ofmemory used across all VMs that use predefined machine types and combinesthe resources to qualify for the largest sustained usage discounts possible.
Assume you run the following two VMs in theus-central1 region duringa month:
- For the first half of the month, you run an
n1-standard-4VM with4 vCPUs and 15 GB of memory - For the second half of the month, you run a larger
n1-standard-16VMwith 16 vCPUs and 60 GB of memory
In this scenario, Compute Engine reorganizes these machine types intoindividual vCPU and memory resources and combines their usage to createthe following resources:
- 4 vCPUs for a full month
- 12 vCPUs for half of the month
- 15 GB of memory for a full month
- 45 GB of memory for half of the month
For example, you can see how the sustained use discounts apply to the vCPUsfor this scenario:
(4 vCPUs x $0.031611 x 730 hours) x 0.7 for the 30% full-month discount = $64.612884
(12 vCPUs x $0.031611 x 365 hours) x 0.9 for the 10% half-month discount = $124.610562
(15 GB x $0.004237 x 730 hours) x 0.7 for the 30% full-month discount = $32.476605
(45 GB x $0.004237 x 365 hours) x 0.9 for the 10% half-month discount = $62.6334525
Sustained use discounts for GPUs
For GPU devices, Compute Engine calculates sustained usediscounts based on the number of a GPU model that you have attached to runningVMs during the month. You can receive sustained use discounts only onGPUs of the same model. Sustained use discounts for GPUs are calculatedseparately from VM machine type, vCPU, and memory discounts.
For example, consider a scenario where you have two VMs with differentnumbers of GPUs that run at different non-overlapping times of the month.Compute Engine breaks down the number of GPUs used across allVMs and combines them to qualify for the biggest sustained usagediscounts possible.
If you run one VM with 1 GPU for the first half of the month, andthen run another VM with 4 GPUs for the second half of the month,Compute Engine calculates discounts for these GPUs as if you hadused 1 GPU for a whole month and 3 remaining GPUs for half of the month.Compute Engine applies the following sustained use discounts:
- A 30% discount off the cost of using 1 GPU for a full month
- A 10% discount off the cost of using the remaining 3 GPUsbecause you used each resource for half of the month
View sustained use discounts
Sustained use discounts automatically appear on your bill at the end ofthe billing cycle. Sustained use discounts are a separate line item combiningall discounts of all machine types for all projects in yourCloud Billing account.
You can view the total sustained use discounts that you receive for each projectand the cost of your VMs in theGoogle Cloud console billing history.
Sustained use discounts and Always Free usage quotas
Google Cloud offersAlways Free usage quotas that providefree use of one e2-micro VM equivalent to the number of total hourswithin the current month. This is enough to run one VM withoutinterruption for the entire month. You cannot receive sustained use discountsfor use of the free tier VM.
What's next
- Review thepricing page to understand the price points fordifferent machine types.
- Considerpurchasing commitments for CUDsif you have a predictable workload.
- Get more savings by usingpreemptible VMs.
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Last updated 2026-02-18 UTC.