Direct answer: at the Azure Retail Prices API on 9 November 2026 (eastus, USD, excluding tax/discounts), Azure Functions' current main options are Flex Consumption and Premium; the old Consumption plan is legacy (Linux retired; Microsoft recommends Flex for new apps). Flex On-Demand: $0.40/million executions, $0.000026/GB-second, with a monthly free grant of 250,000 executions + 100,000 GB-seconds; Always Ready: baseline $0.000004/GB-second (about $10.37/GB-month), execution time $0.000016/GB-second, executions $0.40/million; Premium: $0.173/vCPU-hour + $0.0123/GiB-hour, EP1 (1 vCPU/3.5GiB) about $157.72/month, EP2 about $315.43, EP3 about $630.87. At 512MB and 1 second/run: 1M executions/month Flex about $10.70; 10M about $131.30; 100M about $1,337.30. Break-even: Flex vs Premium EP1 is about 12M executions/month (assuming EP1 capacity); above that, or when VNET/no cold start/larger memory is needed, choose Premium.
This guide is for Azure application platform, SRE, serverless development and FinOps teams. It explains Flex Consumption/Always Ready/Premium billing units, free grants, 100M-scale TCO, Flex-vs-Premium break-even, legacy Consumption migration, hidden costs and a 90-day checklist. Prices come from the Azure Functions pricing page and Azure Retail Prices API (eastus, 9 November 2026); hosting status/limits come from Microsoft Learn's Functions hosting options. Official price facts, editorial calculations and exclusions are kept separate. This is not procurement advice.
(1) Do not default to the old Consumption plan for new projects: Microsoft marks it legacy, Linux is retired, and Flex Consumption is the new serverless path. (2) Flex bills executions + GB-seconds; Premium bills vCPU/memory × time; about 12M executions/month is the rough Flex-vs-EP1 break-even, but confirm EP1 capacity first. (3) Always Ready, retries, storage, logs, VNET and Durable all add cost—do not model the execution unit price alone.
Hosting options: Flex, Premium, Dedicated, Container Apps, legacy Consumption
Flex Consumption is the new serverless mainline: on-demand instances, 512MB/2GB/4GB memory, VNET and optional Always Ready; billed by On-Demand execution time/count. Premium uses pre-warmed fixed workers (1 vCPU/3.5GB, 2/7, 4/14) with no cold start, VNET and more memory; billed by vCPU/memory time, with at least one instance always retained. Dedicated runs on an App Service plan at App Service rates. Container Apps runs containerized functions with the Functions programming model. The old Consumption plan is legacy: Linux is retired, Windows is currently unaffected, and Microsoft recommends migrating to Flex.
| Option | Billing | Best for | Watch |
|---|---|---|---|
| Flex Consumption | Executions + GB-seconds; Always Ready baseline | New serverless, variable/low average | Free 250k executions + 100k GB-s; 512MB/2/4GB |
| Premium | vCPU-hour + GiB-hour | High steady, VNET, no cold start, large memory | At least 1 instance; EP1/2/3 |
| Dedicated | App Service plan | Existing App Service/large compute | App Service rates |
| Container Apps | Container Apps billing | Containerized functions/microservices | Shared container platform |
| Consumption (legacy) | Executions + GB-seconds | Existing Windows apps | Legacy; Linux retired |
Source: Microsoft Learn, Azure Functions hosting options / pricing page (9 November 2026). Editorial summary; regions/features follow official docs.
Unit prices: Flex, Always Ready, Premium
Eastus list prices: Flex On-Demand executions $0.40/million, execution time $0.000026/GB-second, free 250k executions + 100k GB-s/month; Always Ready baseline $0.000004/GB-second (about $10.37/GB-month), execution time $0.000016/GB-second, executions $0.40/million; Premium vCPU $0.173/hour, memory $0.0123/GiB-hour. Legacy Consumption: $0.20/million executions, $0.000016/GB-second, free 1M + 400k GB-s (existing apps only).
| Item | Price (USD) | Note |
|---|---|---|
| Flex On-Demand executions | $0.40/million | Free 250k/month |
| Flex On-Demand time | $0.000026/GB-second | Free 100k GB-s/month |
| Always Ready baseline | $0.000004/GB-second | About $10.37/GB-month; billed while idle |
| Always Ready time | $0.000016/GB-second | Billed while executing |
| Premium vCPU | $0.173/hour | EP1/2/3 |
| Premium memory | $0.0123/GiB-hour | 1/3.5, 2/7, 4/14 |
| Legacy Consumption | $0.20/million + $0.000016/GB-s | Free 1M + 400k GB-s; legacy |
Sources: Azure Retail Prices API (eastus, 9 November 2026) and Azure Functions pricing page. Monthly prices use 730 hours; tax/discounts excluded.
TCO: 1M / 10M / 100M executions (512MB, 1 second)
At 512MB and 1 second/run: 1M executions → 500k GB-seconds. Flex: executions (1M−250k)×$0.40/M=$0.30; time (500k−100k)×$0.000026=$10.40; total $10.70. 10M → 5M GB-seconds: executions 9.75M×$0.40=$3.90; time 4.9M×$0.000026=$127.40; total $131.30. 100M → 50M GB-seconds: executions 99.75M×$0.40=$39.90; time 49.9M×$0.000026=$1,297.40; total $1,337.30. Premium EP1 is fixed at $157.72/month with no execution charge.
| Executions/month | Flex | Premium EP1 | EP2 | EP3 |
|---|---|---|---|---|
| 1M | 10.70 | 157.72 | 315.43 | 630.87 |
| 10M | 131.30 | 157.72 | 315.43 | 630.87 |
| 100M | 1,337.30 | 157.72 | 315.43 | 630.87 |
Editorial calculation: 512MB, 1 second/run; Flex free grant deducted; Premium 730 hours, EP1 1 vCPU/3.5GiB, EP2 2/7, EP3 4/14; storage/logs/egress/tax/discounts excluded. Premium capacity depends on concurrency/instances—benchmark.
Break-even: Flex vs Premium
Flex variable cost per 512MB/1-second run is about $0.40/million + 500k GB-s × $0.000026 = $13.00/million → about $13.40/million including executions. Premium EP1 fixed at $157.72/month; rough break-even = 157.72÷13.40 ≈ 11.77M executions/month; with the free grant, about 12M. EP2 $315.43 → about 23.54M; EP3 $630.87 → about 47.08M. Above those volumes, with sufficient EP capacity, Premium is cheaper; VNET/no cold start/large memory can justify Premium even below break-even.
| Comparison | Formula | Conclusion |
|---|---|---|
| Flex vs EP1 | 157.72 ÷ 13.40/M | About 11.77M/month; ~12M with free grant |
| Flex vs EP2 | 315.43 ÷ 13.40 | About 23.54M/month |
| Flex vs EP3 | 630.87 ÷ 13.40 | About 47.08M/month |
| Always Ready vs On-Demand | baseline 10.37/GB-month + 0.000016/GB-s | Reduces cold start; baseline bills while idle |
| Legacy vs Flex | 0.20/M + 0.000016/GB-s vs 0.40 + 0.000026 | Legacy cheaper but legacy; new apps use Flex |
Editorial calculation: 512MB, 1 second/run; Premium capacity/concurrency needs benchmarking; storage/logs/egress/tax/discounts excluded.
Hidden costs: seven items beyond the execution price
Common add-ons: storage account (created by default per function app, outside the free grant), egress/network (VNET/private endpoints/cross-region), retries (each retry counts as an execution/GB-second), Always Ready baseline (billed while idle, about $10.37/GB-month), Application Insights/logs (ingestion/retention), Durable Functions (orchestration/storage/activity calls), Premium minimum instance (at least one, billed while idle) and legacy Consumption migration (code/test/downtime risk).
| Cost item | Trigger | Control |
|---|---|---|
| Storage account | Created by default | Cleanup/lifecycle/tiering |
| Egress/network | VNET/private endpoints/cross-region | Same region, compression, on demand |
| Retries | Errors/retry policy | Idempotency, limit retries |
| Always Ready | Cold-start reduction | Right-size instances; monitor utilization |
| Logs/App Insights | Sampling/retention | Sampling, retention, filters |
| Durable | Orchestration/activities | Combine activities, control history |
| Premium minimum instance | At least one | Choose EP by throughput; avoid overprovisioning |
Sources: Azure Functions pricing/hosting docs (9 November 2026). Editorial summary; billing follows official pages and bills.
How to choose: new projects, steady state, containers and migration
New serverless/variable/low average → Flex Consumption; high steady state (about >12M executions/month), VNET, no cold start, large memory → Premium; containerized/shared with microservices → Container Apps; existing App Service/large compute → Dedicated; existing legacy Consumption → plan migration to Flex (Linux retired; Windows should migrate early too). Use Always Ready to reduce cold start, but calculate idle cost as baseline × GB × time.
| Scenario | Prefer | Check first |
|---|---|---|
| New serverless/variable/low volume | Flex Consumption | Memory size, free grant, cold start |
| High steady/>12M executions | Premium EP1/2/3 | Capacity/concurrency, VNET |
| No cold start/large memory | Premium + Always Ready | Minimum instances, baseline |
| Containerized/microservices | Container Apps | Container Apps billing |
| Existing App Service | Dedicated | Plan headroom |
| Legacy Consumption | Migrate to Flex | Linux retirement/Windows timeline |
Editorial selection framework, not a vendor recommendation; features/compliance/regional availability follow official docs and business requirements.
90-day checklist
Use the first 90 days to close “executions/GB-seconds baseline → option → pilot → benchmark → cutover → review.” Weeks 1-2: pull executions, average duration, memory, retries and concurrency; weeks 2-4: calculate Flex/Premium break-even and Always Ready needs; weeks 4-6: pilot Flex and test cold start; weeks 6-8: benchmark Premium capacity/VNET; weeks 8-10: cut over/migrate legacy Consumption; weeks 10-12: cost review, tune memory/concurrency/retention. Do not choose by “per-million” unit price alone.
FAQ
How is Azure Functions billed?
Flex Consumption bills executions ($0.40/million) + GB-seconds ($0.000026), free 250k executions + 100k GB-s; Always Ready adds baseline $0.000004/GB-second; Premium bills vCPU $0.173/hour + memory $0.0123/GiB-hour.
Can we still use the old Consumption plan?
It is legacy: Linux is retired, Windows is currently unaffected but gets no new features; Microsoft recommends Flex for new serverless and migration for existing apps.
How much is 1M executions/month?
At 512MB/1 second: Flex about $10.70; Premium EP1 about $157.72, EP2 $315.43, EP3 $630.87. Excludes storage/logs/egress/tax.
What about 100M executions/month?
Flex about $1,337.30; Premium EP1 $157.72 (if capacity suffices), EP2 $315.43, EP3 $630.87. High steady state usually favors Premium.
Flex or Premium?
About 12M executions/month is the rough Flex-vs-EP1 break-even; above that or when VNET/no cold start/large memory is needed, choose Premium. Below that, variable/low average workloads favor Flex.
Is Always Ready worth it?
Yes when reducing cold start matters; baseline is about $10.37/GB-month and bills while idle, execution time $0.000016/GB-second. Calculate idle cost by instances/GB/time.
Why is Premium more expensive?
It bills vCPU/memory time with at least one always-on instance, providing pre-warmed workers/no cold start/VNET/larger memory; EP1 is about $157.72/month, suited to high steady state or SLA workloads.
Can we compare only the per-million price?
No. Flex also has GB-seconds; Premium is fixed compute; memory/duration/retries/Always Ready change the ranking. Model actual executions/GB-seconds.
Research method and limitations
This article separates “official price facts” from “editorial calculations.” Flex On-Demand/Always Ready, Premium vCPU/memory and legacy Consumption prices come from the Azure Functions pricing page and Azure Retail Prices API (eastus, 9 November 2026); hosting status, Flex/Premium/Dedicated/Container Apps, Linux Consumption retirement and worker sizes come from Microsoft Learn's Functions hosting options. TCO, break-even, hidden costs and the 90-day checklist are editorial.
Eight limitations: (1) only eastus list prices, excluding tax/discounts/enterprise agreements; (2) 512MB/1 second/run and 730 hours/month; (3) storage/logs/egress/VNET/Durable combinations are excluded; (4) Premium capacity/concurrency needs benchmarking—do not extrapolate from the EP1 fixed price alone; (5) Always Ready instance count/memory/utilization change cost; (6) Flex savings plan 1/3-year discounts are not fully modeled; (7) Container Apps/Dedicated billing details are out of scope; (8) prices/features change, so recheck official pages and bills before purchase.
Sources and basis
- Microsoft Azure, Azure Functions Pricing: azure.microsoft.com/en-us/pricing/details/functions. Flex/Premium/Consumption prices, free grants. Accessed 9 November 2026.
- Azure Retail Prices API (productName contains Functions/Flex Consumption, eastus): prices.azure.com/api/retail/prices. $0.40/million, 0.000026, 0.000004/0.000016, 0.173/0.0123. Accessed 9 November 2026.
- Microsoft Learn, Azure Functions hosting options: learn.microsoft.com/azure/azure-functions/functions-scale. Flex/Premium/Dedicated/Container Apps, Consumption retirement, worker sizes. Accessed 9 November 2026.
Data cut-off 9 November 2026; prices/availability follow the Azure official page and bill; this is not procurement, commercial or legal advice.