Free Erlang traffic calculators

Eight online Erlang traffic calculators. Use them to size your telecom trunk groups, calculating Voice over IP bandwidth or estimate the staffing requirements of your call center.

Online Erlang calculators

Free Erlang traffic calculators

We published these tools, the world’s first free online Erlang calculators, in 1996, and they remain the most popular aspect of our web site. Revamped for 2019, you can use these calculators to work out how many telephone lines you need, how much bandwidth you should reserve for VoIP or how many agents you need at your inbound call center.

They are based on the industry-standard Erlang traffic models, established in the first half of the last century to analyse telecommunications systems.

  • Erlang B calculator
    Estimate how many lines you need in your trunk groups if you know that traffic that will be offered to your system.
  • Erlang C calculator
    Estimate how many agents or operators you need to answer calls at your inbound call center or help desk.
  • Call center calculator
    Combining Erlang B and Erlang C, this calculator estimates how many agents and lines you need at your call center over a five hour period.
  • Call minutes calculator
    Estimate how many lines your telecom system needs if know the daily minutes it must switch.
  • VoIP bandwidth calculator
    Calculate the bandwidth you require to transport a fixed number of voice paths through your IP network.
  • Erlang bandwidth calculator
    Estimate how much bandwidth you need to carry your busy hour traffic in Erlangs.
  • Extended Erlang B
    Similar to Erlang B but takes into account that a percentage of calls are immediately repeated if they are blocked.
  • Engset calculator
    Estimate how many lines your trunk groups need when you have a finite number of traffic sources.

Professional Windows versions

We offer Erlang traffic calculators and add-ins for Excel and have become the preferred supplier of industry-standard Erlang calculation solutions for the world’s largest companies. We have sold software to tens of thousands of companies in 125 countries. Prices start at only 49 US dollars for lifetime use and free upgrades.

“I’m really happy with my decision to purchase this software from Westbay Engineers. This is the level of Service Quality that we all expect, and your company is doing an outstanding job is this area. You always have a quick answer and fulfil my expectations.”
Osvaldo Velarde, Citicorp