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Network Load Balancer Capacity Calculator

Work out NLCU consumption for TCP, UDP or TLS listeners, spot the billing dimension and price the monthly charge.

About Network Load Balancer Capacity Calculator

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.

Formula

Network Load Balancer Capacity

NLCUs = max(new flows ÷ new-flow allowance, active flows ÷ active-flow allowance, GB per hour ÷ 1), with allowances set by the listener protocol.

1
GB per hour of processed bytes included in one NLCU
new-flow allowance
800 per second for TCP, 400 for UDP, 50 for TLS
active-flow allowance
100,000 per minute for TCP, 50,000 for UDP, 3,000 for TLS

Worked example

With the default values below, Network Load Balancer Capacity Calculator returns NLCUs Billed of 540.00. Change any input above and every figure here is recalculated in your browser.

Inputs used

Listener protocolone of TCP — 800 new and 100,000 active flows per unit, UDP — 400 new and 50,000 active flows per unit, TLS — 50 new and 3,000 active connections per unit
TCP — 800 new and 100,000 active flows per unit
New flows or connections per secondminimum 0 flows/s
800 flows/s
Active flows in a one-minute windowminimum 0 flows
250,000 flows
Processed bandwidthminimum 0 Mbps
1,200 Mbps
Price per NLCU-houraccepts 0–2 USD
0.006 USD
Billable hours per monthaccepts 1–744 hours
730 hours

Results

NLCUs Billed
540.00
Billing Dimension
Processed bytes
Processed Bytes NLCUs
540.00
New Flow NLCUs
1.00
Active Flow NLCUs
2.50
Monthly NLCU Charge
$2,365.20

Step by step

  1. 1Values used
  2. 2Network Load Balancer Capacity
  3. 3NLCUs Billed= 540.00
  4. 4Billing Dimension= Processed bytes
  5. 5Processed Bytes NLCUs= 540.00
  6. 6New Flow NLCUs= 1.00
  7. 7Active Flow NLCUs= 2.50
  8. 8Monthly NLCU Charge= 2,365.20

Assumptions and limits

  • The result is derived only from the 6 inputs listed above. Anything not among them is not part of the calculation.
  • In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
  • Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

How is Network Load Balancer Capacity calculated?

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.

Why does Network Load Balancer Capacity matter?

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.

What values do I need to enter?

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.

Why is TLS so much more expensive in NLCU terms?

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.

Does the NLB hourly charge appear here?

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.

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