Network Load Balancer Capacity Calculator

NLCUs = max(new flows ÷ new-flow allowance, active flows ÷ active-flow allowance, GB per hour ÷ 1), with allowances set by the listener protocol. A Network Load Balancer bills on the highest of three NLCU dimensions, and the flow allowances depend on the listener protocol because TLS termination is far more expensive than passing TCP through: a TLS listener gets only 50 new connections per second per unit against 800 for plain TCP. The bytes dimension is protocol independent at 1 GB per hour, so a high-bandwidth TCP workload is usually billed on bytes while a TLS-heavy API is billed on connections.

Moving TLS termination from an NLB to an ALB, or reusing connections instead of reconnecting, can cut NLCU consumption by an order of magnitude for the same user-visible traffic.

This calculator takes 6 inputs: Listener protocol, New flows or connections per second, Active flows in a one-minute window, Processed bandwidth, Price per NLCU-hour, Billable hours per month. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

Each new TLS connection needs a full handshake with asymmetric cryptography on the load balancer. AWS reflects that cost by allowing only 50 new TLS connections per second per NLCU, sixteen times fewer than plain TCP, so connection reuse matters far more on a TLS listener.

No — this calculator isolates the NLCU component. Add the fixed per-hour charge with the Elastic Load Balancer Cost Calculator, and confirm both the NLCU price and the hourly rate for your region with AWS, since they vary and change over time.