Group product manager Paul Nash wrote that the new pricing model will have a one-minute minimum, and will apply to Compute Engine, Container Engine, Cloud Dataproc, and App Engine flexible environment VMs.
The changes came into force yesterday and can be applied to all VMs, including Preemptible VMs and VMs running Google's premium OS images, such as Windows Server, Red Hat Enterprise Linux (RHEL), and SUSE Enterprise Linux Server.
GCP already offers per-second billing on its Persistent Disks, having done so since 2013, as well as committed-use discounts and GPUs, but now these new offerings join them.
"In most cases, the difference between per-minute and per-second billing is very small - we estimate it as a fraction of a percent," wrote Nash.
"On the other hand, changing from per-hour billing to per-minute billing makes a big difference for applications (especially websites, mobile apps and data processing jobs) that get traffic spikes.
"The ability to scale up and down quickly could come at a significant cost if you had to pay for those machines for the full hour when you only needed them for a few minutes."
Google has been quick to follow AWS, which last week announced it would introduce per-second billing for EC2 and EBS across all AWS regions. Customers' bills will reflect this change from 2 October, but GCP's changes are effective immediately. The pricing change aims to make billing more accurate than per-minute models for short-term cloud usage.