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Application Load Balancer Capacity Calculator

Compute all four ALB LCU dimensions, see which one you are billed on, and price the resulting capacity-unit charge.

About Application Load Balancer Capacity Calculator

An Application Load Balancer measures four things every hour — new connections, active connections, processed bytes and rule evaluations — converts each into LCUs against its own allowance, and charges you for the largest of the four. Rule evaluations are requests per second multiplied by the rules processed beyond the ten that are free, which is why a long listener rule chain can quietly become the dimension you pay for even when bandwidth is modest. Knowing which dimension drives the bill tells you what to optimise: connection reuse and keep-alive for the connection dimensions, compression for bytes, and consolidating listener rules for evaluations.

Formula

Application Load Balancer Capacity

LCUs = max(new connections ÷ 25, active connections ÷ 3000, GB per hour ÷ 1, rule evaluations per second ÷ 1000).

1
GB per hour of processed bytes included in one LCU
25
New connections per second included in one LCU
1000
Rule evaluations per second included in one LCU
3000
Active connections per minute included in one LCU

Worked example

With the default values below, Application Load Balancer Capacity Calculator returns LCUs Billed of 180.00. Change any input above and every figure here is recalculated in your browser.

Inputs used

New connections per secondaccepts 0–200,000 conn/s
120 conn/s
Active connections in a one-minute windowminimum 0 connections
90,000 connections
Processed bandwidthminimum 0 Mbps
400 Mbps
Requests per secondminimum 0 req/s
2,500 req/s
Rules processed per requestaccepts 0–100 rules
14 rules
Price per LCU-houraccepts 0–2 USD
0.008 USD

Results

LCUs Billed
180.00
Billing Dimension
Processed bytes
Processed Bytes LCUs
180.00
Rule Evaluation LCUs
10.00
New Connection LCUs
4.80
Active Connection LCUs
30.00
Monthly LCU Charge
$1,051.20

Step by step

  1. 1Values used
  2. 2Application Load Balancer Capacity
  3. 3LCUs Billed= 180.00
  4. 4Billing Dimension= Processed bytes
  5. 5Processed Bytes LCUs= 180.00
  6. 6Rule Evaluation LCUs= 10.00
  7. 7New Connection LCUs= 4.80
  8. 8Active Connection LCUs= 30.00

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 Application Load Balancer Capacity calculated?

LCUs = max(new connections ÷ 25, active connections ÷ 3000, GB per hour ÷ 1, rule evaluations per second ÷ 1000). An Application Load Balancer measures four things every hour — new connections, active connections, processed bytes and rule evaluations — converts each into LCUs against its own allowance, and charges you for the largest of the four. Rule evaluations are requests per second multiplied by the rules processed beyond the ten that are free, which is why a long listener rule chain can quietly become the dimension you pay for even when bandwidth is modest.

Why does Application Load Balancer Capacity matter?

Knowing which dimension drives the bill tells you what to optimise: connection reuse and keep-alive for the connection dimensions, compression for bytes, and consolidating listener rules for evaluations.

What values do I need to enter?

This calculator takes 6 inputs: New connections per second, Active connections in a one-minute window, Processed bandwidth, Requests per second, Rules processed per request, Price per LCU-hour. 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 my LCU count higher than my traffic suggests?

Because only the highest dimension counts. Short-lived connections without keep-alive can push the new-connection dimension to dozens of LCUs while bandwidth sits near zero, and you pay the connection figure.

Do Lambda targets change the bytes allowance?

Yes. The processed-bytes allowance is 1 GB per hour per LCU for instance, container and IP targets, but only 0.4 GB per hour when the target is a Lambda function, so the same traffic costs more LCUs. Confirm the current allowances and the LCU price for your region with AWS.

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