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Min instances cost calculator for Cloud Functions and Cloud Run

Minimum instances keep your functions warm, and you pay for them even when no requests arrive. Enter each function or service that sets min instances to see what keeping them warm costs per month, from Google’s published list prices.

Your functions and services

Billing mode

  • $9.86 a month

Idle cost of your min instances

$9.86 a month

$118.32 a year

Each instance is priced for 730 hours a month at $0.0000025 per vCPU-second and $0.0000025 per GiB-second, assuming it sits idle the whole time; time spent handling requests is billed at the active rate instead. Prices are Google’s on-demand list prices for us-central1, checked 2026-10-12. Tier 2 regions cost more, committed use discounts cost less, and the monthly free tier (180,000 vCPU-seconds and 360,000 GiB-seconds) is shared with the rest of your Cloud Run usage on the billing account. Check the Cloud Run pricing page for your region.

Want the whole bill checked?

Min instances are one line of a Firebase bill. The Firebase Cost-Cut Audit prices every Cloud Run service and Cloud Function from measured usage, including Firestore reads, schedules, retries, logging and AI usage. It ranks each saving by dollars a month and risk and gives you the exact commands to apply it. $750, 5 business days, read-only access.

Pay $750 & startHow the Cost Audit works

Questions

Are minimum instances billed when there is no traffic?
Yes. Instances kept warm by a minimum instances setting are billed while idle. With request-based billing they are billed at a lower idle rate; idle instances that are not minimum instances are not charged.
Do Firebase Cloud Functions use these prices?
Cloud Functions for Firebase (2nd gen) run on Cloud Run, so their CPU and memory are billed at Cloud Run rates. First-generation functions use a different pricing model and are not covered by this calculator.
How do I find which functions set min instances?
Search your functions code for minInstances, including in setGlobalOptions, or open each service in the Cloud Run console, where the minimum instances setting is shown. The guide linked below walks through both.
Why is my actual bill different?
This calculator only covers idle min instances in us-central1 at list prices. Your bill also includes active request time, other regions, the free tier, discounts, Firestore, Storage, networking and logging.

Next: what min instances cost and when to cut them and how to cut your Firebase bill.

Fixed-price Firebase help

Fixed scope, fixed price, paid upfront. The work happens in writing; no call needed.