AWS · Free tool

AWS ALB cost calculator

ALB looks like $0.0225 an hour and goes home. Then the LCU column on your invoice ships at 4x the base. Plug in real traffic, see which of the four dimensions is driving your bill, and where to cut.

Estimated monthly ALB cost

$0 per year

Component	Monthly	Detail
Hourly base cost	$0	1 ALB × 730 h × $0.0225
LCU cost	$0	0 LCU-hours × $0.008

LCU per dimension (max wins)

Dimension	LCU
New connections	0 LCU
Active connections	0 LCU
Processed bytes	0 LCU
Rule evaluations	0 LCU
Billed LCU (max)	0 LCU

Driving dimension: processed bytes

If your monthly ALB bill looks high, check these first: idle ALBs in dev or stage accounts, one ALB per microservice that could consolidate behind host or path rules, massive payloads pushed through ALB instead of S3 or CloudFront, deep regex rules evaluated on every request, and public ALBs doing service-to- service traffic that could move behind an internal NLB.

The line item nobody watches

ALB is the EC2 of L7. Quiet, ubiquitous, and somehow always $4,000 a month bigger than anyone expected. The hourly base is 22 cents a day. The LCU column is where the real bill hides, and the LCU is the maximum of four dimensions, so tuning one knob does nothing if a different knob is the one driving your bill.

We wrote up the full audit pattern in the line item nobody watches: how to read CloudWatch LCU metrics, where consolidation actually saves money, and the three patterns that quietly double an ALB bill.

Frequently asked

How is ALB priced exactly?

Two components. First, an hourly base of $0.0225 per ALB hour, regardless of traffic. Second, LCU-hours: a Load Balancer Capacity Unit is the maximum across four dimensions (new connections per second, active connections per minute, processed bytes per hour, rule evaluations per second). One LCU-hour costs $0.008 in most regions. Your monthly bill is base hours plus LCU hours.
Which dimension usually drives the LCU bill?

Processed bytes and rule evaluations dominate for most customers. Processed bytes converts at 1 GB per hour per LCU for HTTP/HTTPS traffic, so 30 GB/hour means 30 LCUs from that dimension alone. Rule evaluations bite teams with elaborate path-based routing, since every request that touches more than 10 rules adds to the LCU. New connections and active connections matter for high-fanout APIs and websocket fleets.
When should I use NLB instead of ALB?

NLB is L4 (TCP/UDP) and bills per NLCU, which is cheaper if your traffic is mostly bytes through, light connections, and you do not need HTTP routing, WAF, or path-based rules. ALB is L7 and necessary for host/path routing, redirects, fixed responses, OIDC auth, and Lambda targets. Most teams keep ALB for the public edge and use NLB internally for service-to-service paths.
Do I pay for idle ALBs?

Yes, the hourly base of $0.0225 runs whether traffic is one request a day or one million. That is $16.43 per ALB per month before any traffic. Teams with dozens of stale dev or stage ALBs hidden in old accounts often find $500-$1,500 per month evaporating. Audit your inventory and delete the ones with zero target health.