NLB cost explained: Network Load Balancer pricing and NLCUs

Quick answer

A Network Load Balancer bills about $0.0225 per hour (roughly $16.20 per month) plus a Network Load Balancer Capacity Unit (NLCU) charge of about $0.006 per NLCU-hour, cheaper than the ALB's $0.008 LCU. One NLCU covers dimensions per protocol: for TCP, 800 new connections per second, 100,000 active connections, and 1 GB processed per hour. You are billed on the highest dimension. The NLB shines for high-throughput TCP and UDP pass-through where its higher connection allowances and lower per-unit rate make it cheaper than an ALB. The rule: use an NLB for layer-4 traffic and an ALB when you need layer-7 routing.

The Network Load Balancer is AWS's layer-4 load balancer, built for high-throughput TCP and UDP traffic. Its pricing mirrors the ALB's structure, an hourly fee plus a capacity-unit charge, but the capacity unit is different, cheaper per unit, and measured with allowances tuned for connection-heavy workloads. For the right traffic, that makes the NLB the cheaper choice.

The pricing structure

Component	Rate
Hourly fee	~$0.0225/hr (~$16.20/mo)
NLCU fee	~$0.006 per NLCU-hour

Every NLB pays the hourly fee, about $16.20 a month, just to exist. On top of that, you pay for Network Load Balancer Capacity Units at about $0.006 each per hour, a lower rate than the ALB's $0.008 LCU.

The NLCU dimensions

Dimension (TCP)	One NLCU equals
New connections	800 per second
Active connections	100,000 per minute
Processed bytes	1 GB per hour

As with the ALB, the NLB measures each dimension per hour and bills you on the highest one, not the sum. The key difference is the connection allowances: an NLCU covers 800 new connections per second against the ALB's 25, and 100,000 active connections against the ALB's 3,000. So for connection-heavy workloads, the same traffic consumes far fewer NLCUs than LCUs, and at a lower per-unit rate. Processed bytes are billed the same 1 GB per unit on both. Note that UDP and TLS have their own per-unit allowances.

Why the NLB is cheaper for the right traffic

Consider a service handling 400 new TCP connections per second. On an NLB that is 0.5 NLCUs; on an ALB the same 400 connections per second would be 16 LCUs. Even before the lower per-unit rate, the NLB's generous connection allowance makes it dramatically cheaper for connection-dominated, low-byte traffic. For byte-dominated traffic the two are closer, since both bill 1 GB per unit, but the NLB's cheaper unit still edges ahead. This is the core of the ALB versus NLB cost decision.

When to pay for an ALB instead

The NLB is layer 4: it forwards TCP and UDP without understanding HTTP. If you need host- and path-based routing, HTTP header manipulation, redirects, authentication, or a web application firewall attached, you need the layer-7 ALB and its features are worth the higher capacity-unit rate. Use the NLB for raw TCP or UDP throughput, extreme connection volumes, static IP requirements, and low-latency pass-through, and the ALB for smart HTTP routing.

Because the capacity-unit bill depends on connection and byte volume, estimate them before choosing. Price your load balancer against the resource catalog so the NLB and ALB costs are compared on your real traffic before you commit to one.

FAQ

How is a Network Load Balancer priced?

About $0.0225 per hour (roughly $16.20 a month) plus a Network Load Balancer Capacity Unit charge of about $0.006 per NLCU-hour. One NLCU for TCP covers 800 new connections per second, 100,000 active connections, and 1 GB processed per hour. You are billed on the highest dimension each hour, not the sum, so connection-heavy and byte-heavy workloads bill differently.

Is an NLB cheaper than an ALB?

For layer-4 TCP and UDP traffic, usually yes. The NLB's NLCU costs about $0.006 versus the ALB's $0.008 LCU, and its connection allowances are far larger: 800 new connections per second per unit versus the ALB's 25. So connection-heavy traffic consumes far fewer capacity units on an NLB. For byte-dominated traffic the two are closer since both bill 1 GB per unit, but the NLB's cheaper unit still edges ahead.

What is an NLCU?

A Network Load Balancer Capacity Unit, the usage-based billing unit for an NLB at about $0.006 each per hour. For TCP it covers 800 new connections per second, 100,000 active connections per minute, and 1 GB of processed bytes per hour, with separate allowances for UDP and TLS. The NLB measures each dimension and bills on the highest one, like the ALB's LCU but with more generous connection allowances.

When should I use an NLB instead of an ALB?

Use an NLB for raw TCP or UDP throughput, extreme connection volumes, static IP requirements, and low-latency pass-through where you do not need HTTP awareness. Use an ALB when you need layer-7 features like host- and path-based routing, HTTP header manipulation, redirects, authentication, or an attached web application firewall. The NLB is cheaper for layer-4 traffic; the ALB's features justify its higher rate for HTTP.

How do I reduce NLB cost?

Identify the dominant NLCU dimension in CloudWatch. Because the NLB's connection allowances are large, byte volume often dominates, so compressing or offloading large transfers helps. Consolidating multiple TCP services behind one NLB saves the per-hour base fee versus running several. And confirming the NLB is the right choice versus an ALB for your traffic avoids paying ALB rates for pass-through traffic.

How does C3X help with NLB cost?

C3X prices your Network Load Balancer from Terraform before you deploy, including the base fee, so the load balancer cost is visible in the pull request. Combined with expected connection and byte volumes, that helps you compare the NLB against an ALB and confirm the layer-4 choice is cheaper for your traffic, at design time rather than after the capacity-unit charges appear on the bill.

What to do next

Compare NLB and ALB cost before you deploy. C3X reads your Terraform and prices your resources against a live catalog. Start with the quickstart.