Azure Event Hubs vs Service Bus cost: streaming vs messaging pricing

Quick answer

Event Hubs and Service Bus serve different needs and price differently. Event Hubs is a high-throughput streaming platform priced mainly by throughput units at about $0.03 per hour each (roughly $22 per month per TU) plus about $0.028 per million events, ideal for massive event ingestion. Service Bus is an enterprise message broker: its Standard tier costs a small base fee plus about $0.05 per million operations, and its Premium tier bills per messaging unit at roughly $0.928 per hour (about $677 per month) for isolation and predictable performance. The rule: Event Hubs for high-volume streaming and telemetry, Service Bus for transactional messaging with ordering and dead-lettering.

Event Hubs and Service Bus are both Azure messaging services, but they are built for different jobs and priced on different models, so comparing them on cost only makes sense once you know which one fits the workload. Event Hubs is a firehose for high-volume event streams; Service Bus is a broker for reliable enterprise messaging. Choosing the wrong one is both a functional and a cost mistake.

How each is priced

Service	Primary cost basis	Best for
Event Hubs	Throughput units + per-million events	High-volume streaming
Service Bus Standard	Base fee + per-million operations	Moderate messaging
Service Bus Premium	Per messaging unit (dedicated)	High-scale, isolated messaging

Event Hubs Standard bills each throughput unit at about $0.03 per hour, roughly $22 per month, where a TU provides a defined ingress and egress capacity, plus about $0.028 per million events captured. Service Bus Standard bills a small base fee plus about $0.05 per million operations. Service Bus Premium bills per messaging unit at roughly $0.928 per hour, about $677 per month per unit, for dedicated, predictable capacity.

Event Hubs: cost scales with throughput

Event Hubs is cheap per event at scale because a handful of throughput units can ingest enormous volumes. Ingesting a steady telemetry stream might need only a few TUs, costing tens to low hundreds of dollars a month for millions of events. Auto-inflate lets TUs scale with load so you are not over-provisioning, and the per-event charge is tiny. For streaming, log aggregation, and telemetry pipelines, this is far cheaper than pushing the same volume through a per-operation broker, as the Event Hubs cost guide details.

Service Bus: cost scales with operations and features

Service Bus charges per operation on Standard, so cost tracks message count, and it offers features Event Hubs does not: ordered delivery, dead-lettering, sessions, transactions, and topics with subscriptions. For moderate transactional messaging, Standard is inexpensive. But at high volume the per-operation cost climbs, and predictable performance requires Premium's per-messaging-unit pricing, which is a fixed monthly cost per unit regardless of volume, covered in the Service Bus cost guide.

When each is cheaper

For high-volume, fire-and-forget event streams, Event Hubs is dramatically cheaper because throughput units ingest millions of events for a low per-TU fee. For transactional workflows needing ordering, dead-lettering, and guaranteed delivery at moderate volume, Service Bus Standard is cheap and functionally right. At very high messaging volume with strict requirements, Service Bus Premium's fixed messaging-unit cost can be predictable but expensive, so confirm you need its guarantees. Using Service Bus for raw high-volume streaming, or Event Hubs for transactional workflows, tends to cost more and fit worse.

Choosing on cost and fit

Start from the workload: streaming telemetry and events point to Event Hubs; transactional messaging with ordering and delivery guarantees points to Service Bus. Then size throughput units or messaging units to the real volume. Price both services against the resource catalog before you deploy so the cost curve of each, throughput units versus operations or messaging units, is clear for your expected volume.

FAQ

How are Event Hubs and Service Bus priced differently?

Event Hubs bills mainly by throughput units at about $0.03 per hour each (roughly $22 per month) plus about $0.028 per million events, suited to high-volume streaming. Service Bus Standard bills a small base fee plus about $0.05 per million operations, and Service Bus Premium bills per messaging unit at roughly $0.928 per hour (about $677 per month) for dedicated capacity. They price on throughput versus operations respectively.

When is Event Hubs cheaper than Service Bus?

For high-volume, fire-and-forget event streams like telemetry, logs, and metrics. A few throughput units can ingest millions of events for a low per-TU fee plus a tiny per-event charge, far cheaper than pushing the same volume through Service Bus's per-operation pricing. Event Hubs is built for streaming scale, so raw high-volume ingestion is its cost sweet spot.

When should I use Service Bus instead of Event Hubs?

When you need enterprise messaging features Event Hubs lacks: ordered delivery, dead-lettering, sessions, transactions, and topics with subscriptions. For moderate transactional messaging, Service Bus Standard is inexpensive and functionally right. Event Hubs is a streaming firehose without these delivery guarantees, so transactional workflows belong on Service Bus even though its per-operation model costs more at high volume.

Is Service Bus Premium worth the cost?

Premium bills a fixed roughly $677 per month per messaging unit for dedicated, isolated, predictable-performance capacity regardless of volume. It is worth it for high-scale messaging with strict performance and isolation requirements, but expensive if you do not need those guarantees. At moderate volume, Standard's per-operation pricing is far cheaper, so confirm you genuinely need Premium's dedicated capacity before choosing it.

How does C3X help compare messaging cost?

C3X prices Event Hubs and Service Bus configurations from Terraform before you deploy, including throughput units and messaging units, so the cost curve of each service is visible in the pull request. That lets you compare streaming versus messaging pricing against your expected volume at design time and avoid using the wrong, more expensive service for the workload.

What to do next

Compare Event Hubs and Service Bus before you deploy. C3X reads your Terraform and prices your resources against a live catalog. Start with the quickstart.