Load Balancer Cost Calculator

About the Load Balancer Cost Calculator

Cloud load balancers distribute incoming traffic across backend targets and are essential for high availability. AWS offers three types: Application Load Balancer (ALB), Network Load Balancer (NLB), and Gateway Load Balancer (GWLB), each with different pricing models.

Pricing has two components: a fixed hourly charge and a variable charge based on Load Balancer Capacity Units (LCUs) or similar metrics. An ALB costs $0.0225/hr ($16.43/mo) plus $0.008 per LCU-hour. The LCU cost depends on new connections, active connections, processed bytes, and rule evaluations.

This calculator estimates your total load balancer cost based on the number of LBs, the fixed hourly rate, and the variable capacity charge. Use it to compare ALB vs NLB pricing and determine whether consolidating multiple LBs behind a single ALB with path-based routing would save money.

When This Page Helps

Load balancer costs are easy to underestimate. A single ALB serving moderate traffic can cost $20–40/month, but deploying one per microservice quickly multiplies this. Kubernetes clusters often create one ALB per Ingress resource. Understanding the cost model helps you consolidate LBs and choose the right type for your workload.

How to Use the Inputs

1. Enter the number of load balancers you plan to run.
2. Set the hourly rate (e.g., $0.0225 for ALB, $0.0225 for NLB).
3. Enter the estimated LCU consumption per hour per LB.
4. Set the LCU hourly rate (e.g., $0.008 for ALB).
5. Review the cost breakdown per LB and total monthly cost.

Example Calculation

Tips & Best Practices

• Use a single ALB with host-based and path-based routing rules instead of one ALB per service.
• NLB is cheaper for TCP/UDP traffic and supports static IPs; use it for gRPC, databases, and IoT.
• ALB supports WebSocket, HTTP/2, and gRPC natively with content-based routing.
• For Kubernetes, use the AWS Load Balancer Controller with IngressGroup to share one ALB across namespaces.
• Monitor LCU consumption in CloudWatch to identify which dimension (connections, bytes, rules) drives cost.
• Consider internal LBs for service-to-service communication; they have the same pricing but avoid internet data transfer.

ALB vs NLB vs CLB Pricing Comparison

ALB: $0.0225/hr + $0.008/LCU-hr. Best for HTTP/HTTPS with routing rules. NLB: $0.0225/hr + $0.006/NLCU-hr. Best for TCP/UDP with extreme performance. Classic LB (deprecated): $0.025/hr + $0.008/GB. Avoid for new deployments. GCP HTTP(S) LB: $0.025/hr + $0.008–$0.012/GB. Azure Standard LB: free for VMs; Application Gateway starts at $0.20/hr.

Kubernetes Ingress and Load Balancer Costs

By default, each Kubernetes Service of type LoadBalancer creates a new cloud LB. With 10 services, that is $164/month in ALB fixed fees alone. Use the AWS Load Balancer Controller with IngressGroup annotation to share one ALB across multiple Ingress resources, reducing costs by 80–90%.

Monitoring LCU Consumption

CloudWatch metrics ConsumedLCUs, ActiveConnectionCount, and ProcessedBytes help identify your cost drivers. If rule evaluations dominate LCU usage, simplify routing rules or consolidate redundant rules.

Frequently Asked Questions

• What is an LCU?

  A Load Balancer Capacity Unit (LCU) measures ALB resource consumption across four dimensions: new connections, active connections, processed bytes, and rule evaluations. You are billed for whichever dimension has the highest consumption each hour. A typical low-traffic ALB uses 0.5–2 LCUs/hr.

• ALB or NLB: which should I use?

  Use ALB for HTTP/HTTPS workloads needing content-based routing, sticky sessions, or WAF integration. Use NLB for TCP/UDP, ultra-low latency, static IP, or extremely high throughput. NLB processes packets without terminating connections, making it faster but less feature-rich.

• How much does a single ALB cost per month?

  The minimum cost is the fixed fee: $0.0225/hr × 730 = $16.43/month. With moderate traffic (1–3 LCU/hr), variable cost adds $5.84–$17.52. A typical ALB costs $20–40/month. High-traffic ALBs with many routing rules can cost $50–$100+/month.

• Can I use one ALB for multiple services?

  Yes. ALB supports up to 100 rules per listener. Use host-based rules (api.example.com vs web.example.com) and path-based rules (/api/* vs /static/*) to route traffic to different target groups. This is much cheaper than running separate ALBs.

• What is the Gateway Load Balancer?

  GWLB is designed for third-party virtual appliances like firewalls, IDS/IPS, and deep packet inspection. It operates at Layer 3 using GENEVE encapsulation. Pricing is $0.0125/hr + $0.004/GB processed. It is not a general-purpose load balancer.

• Is there a free tier for load balancers?

  AWS offers 750 hours/month of ALB or NLB in the free tier for the first 12 months, plus 15 LCUs for ALB or 15 GB processed for NLB. After the free tier expires, you pay full price. GCP has no free tier for load balancers.