IIoT, SCADA & Edge Connectivity worked example

MQTT Data Cost at 22% share of telemetry over billed network: a worked example

Suppose share of telemetry over billed network falls to 22%. This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate monthly MQTT or Sparkplug B data spend from messages published per month, average payload size in KB, the share that actually travels over billed network (cellular or cloud egress), and a fixed broker subscription or hosting cost.

The inputs for this scenario

  • MQTT messages published per month: 4,500,000 messages / mo (held at the documented default)
  • Average MQTT payload size: 0.4 KB / message (held at the documented default)
  • Share of telemetry over billed (cellular/egress) network: 22 % (the input this scenario stresses; the baseline uses 30)
  • Fixed broker subscription or hosting cost: 850 $ / mo (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Variable MQTT data cost per month = messages per month × average payload size in KB × share over billed network (the engine treats average payload size as the per-message cost weight).
  • Total MQTT data cost per month works out to 396,850 $ at these inputs, and this is the headline figure for the scenario.
  • Cost per million MQTT messages works out to 0.09 $ / piece at these inputs.
  • Variable MQTT data cost per month works out to 396,000 $ at these inputs.
  • Fixed broker subscription or hosting cost works out to 850 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where share of telemetry over billed network sits at 30% and the headline result is 540,850 $, this scenario comes in 26.62% below the baseline at 396,850 $.
  • It multiplies monthly message count by average payload size and the billed-network share to get variable data cost, then adds your fixed broker/hosting fee for a total monthly MQTT spend. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Total MQTT data cost per month: 396,850 $ (headline result)
  • Cost per million MQTT messages: 0.09 $ / piece
  • Variable MQTT data cost per month: 396,000 $
  • Fixed broker subscription or hosting cost: 850 $

Run it with your numbers

  • To rerun this with your own numbers, open the live MQTT Data Cost calculator, set share of telemetry over billed network to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.