AWS Network Load Balancer Pricing (US-East-1 2025 Guide)

Choosing between an Application Load Balancer (ALB) and a Network Load Balancer (NLB)? The price mechanism is the deciding factor, and it’s more complex than just “layer 4 vs layer 7.”

The Base Hourly Rate (US-East-1)

Both load balancers share the same fixed cost:

• NLB: $0.0225 per hour (~$16.42/month).
• ALB: $0.0225 per hour (~$16.42/month).

If you have 10 load balancers, you pay ~$164/month just for them to exist, even with zero traffic. This is why Shared Ingress is critical in Kubernetes.

The Variable Cost: NLCU vs LCU

Here is where the bills diverge.

AWS Application Load Balancer (ALB)

Uses Load Balancer Capacity Units (LCUs). you are charged for the highest dimension of:

1. New Connections: (25 new connections/sec = 1 LCU)
2. Active Connections: (3,000 active connections = 1 LCU)
3. Bandwidth: (1 GB/hour = 1 LCU)
4. Rule Evaluations: (1,000 rules = 1 LCU)

Verdict: ALB is expensive for High Connection Count (WebSockets) or complex rule sets.

AWS Network Load Balancer (NLB)

Uses Network Load Balancer Capacity Units (NLCUs). You are charged for the highest of:

1. Bandwidth: (Bytes transferred)
2. New Flows: (New connections initiated)
3. Active Flows: (Concurrent connections)

The magic of NLB: It is extremely efficient at handling millions of connections. Usually, the Bandwidth is the only factor that matters for cost.

Hidden Cost: TLS Termination

This is the most common trap.

If you use NLB for HTTPS traffic, you have two choices:

1. TCP Pass-through: NLB sends encrypted traffic to your EC2/Pod. Your specific app does the decryption.
   • NLB Cost: Low (Processing bytes is cheap).
   • Compute Cost: High (Your EC2 CPU burns 10-20% on SSL handshake).
2. TLS Listeners: NLB terminates SSL and sends HTTP to backend.
   • NLB Cost: Expensive. AWS adds a surcharge for TLS processing on NLB.

Which is Cheaper?

1. For pure TCP traffic (Databases, Gaming, IoT): NLB is the clear winner. It handles millions of packets with microsecond latency. ALB literally cannot do this.

2. For Standard Web Apps (Microservices): ALB is often cheaper and simpler. Using an NLB requires you to manage logic (routing, headers) in your app. The operational cost of “reinventing the ALB” in code outweighs the infrastructure savings.

Kubernetes Impact

If you create a Service of type: LoadBalancer in EKS, AWS spins up a Classic LB (or NLB if annotated).

apiVersion: v1
kind: Service
metadata:
  name: my-service
spec:
  type: LoadBalancer # Costs $16/mo

If you have 50 microservices, that’s $800/month in idle load balancer fees.

The Fix: Use an Ingress Controller (AWS Load Balancer Controller). It spins up one single ALB (shared) and routes traffic based on hostnames.

• Cost: $16/month total.
• Savings: $784/month.

[!NOTE] Pro Tip: Check your “Elastic Load Balancing” bill in Cost Explorer. If LCU-Usage is more than 50% of the cost, you are pushing too much traffic for an ALB. Consider moving high-volume endpoints to NLB.