How to Use Sustained Use Discounts in GCP for Cost Savings
In Google Cloud Platform,
Sustained Use Discounts automatically lower the price of virtual machine instances when they run for a significant portion of the billing month. You do not need to configure anything; GCP applies these discounts based on your VM usage hours each month.Syntax
Sustained Use Discounts in GCP do not require explicit syntax or configuration in your code or deployment files. They are automatically applied by GCP based on your VM instance usage.
Key points:
- VM usage hours: Discounts start applying when a VM runs for more than 25% of the month.
- Discount scale: The discount increases with more usage, up to a maximum at 100% usage.
- Applies to: Compute Engine VM instances only.
gcp
None (automatic billing feature)
Example
This example shows how sustained use discounts appear on your billing report after running a VM instance continuously for a month.
bash
gcloud compute instances create example-vm --zone=us-central1-a --machine-type=e2-medium # Run the VM for the whole month # After the month ends, check billing report: gcloud beta billing projects list # Then view billing details in Google Cloud Console under Billing > Reports
Output
Instance 'example-vm' created.
Billing report shows sustained use discount applied automatically based on usage hours.
Common Pitfalls
Common mistakes when expecting sustained use discounts:
- Expecting discounts on short-lived or sporadic VM usage — discounts only apply when usage exceeds 25% of the month.
- Trying to enable discounts manually — sustained use discounts are automatic and cannot be turned on or off.
- Confusing sustained use discounts with committed use discounts, which require upfront commitment.
bash
Wrong approach (does not enable discount): gcloud compute instances create example-vm --zone=us-central1-a --machine-type=e2-medium --no-sustained-use-discount Right approach (no flag needed): gcloud compute instances create example-vm --zone=us-central1-a --machine-type=e2-medium
Output
Error: --no-sustained-use-discount flag does not exist.
Correct: No flags needed; discount applies automatically.
Quick Reference
| Feature | Details |
|---|---|
| Applies to | Compute Engine VM instances |
| Discount start | After 25% monthly usage (~180 hours) |
| Discount max | Up to 30% at 100% usage |
| Configuration | Automatic, no user action needed |
| Difference from committed use | No upfront commitment required |
Key Takeaways
Sustained Use Discounts apply automatically based on VM usage hours each month.
Discounts start after running a VM for more than 25% of the month and increase with usage.
No manual configuration or flags are needed to receive these discounts.
They only apply to Compute Engine VM instances, not other GCP services.
Do not confuse sustained use discounts with committed use discounts, which require upfront commitment.