Back to ToolsWorkforce Management Tools

Free Erlang C Staffing Calculator

Calculate the exact number of agents you need, instantly, no signup.

Interval inputs

Results update live as you type.

calls

Contacts arriving in the interval

sec

Talk time + after-call work

%
sec
x

1.0 keeps your entered volume unchanged

%

Breaks, training, absence, meetings

Required Agents
39agents
Staff to Schedule
56with shrinkage
Achieved Service Level
84.2%
Average Speed of Answer
10.8sec
Occupancy
85.5%
Traffic Intensity
33.33erlangs

About 25.4% of contacts will have to wait in queue with 39 agents handling calls.

Save or share these results

Take a snapshot of the exact inputs and outputs on screen.

Email me these results

Get the full Excel/VBA version

The full Excel/VBA version with live formulas, RTM tracking, and dashboards is free for now.

Results are estimates for planning purposes only and should not replace professional workforce management judgment.

More tools

Explore the rest of the WFM Helper toolkit, or read about the site.

Trending

Service Level Recovery Calculator

Behind on service level mid-month? Get the volume-weighted SL you need for the rest of the period, and see instantly if the target is already unreachable.

Open calculator
Trending

Shrinkage Calculator

Break planned and unplanned off-phone time into a single planning shrinkage percentage and the staff uplift it forces.

Open calculator
Trending

AHT Calculator

Combine talk time, hold and after-call work into average handle time, with a breakdown of where the time actually goes.

Open calculator
Live

Occupancy Calculator

Check how hard your agents are really working, against the healthy 85–92% band, and spot burnout risk before attrition rises.

Open calculator
Live

Service Level Calculator

Reverse Erlang C: given the agents you actually have, see the service level, ASA and occupancy you will achieve.

Open calculator
Live

Attrition Rate Calculator

Calculate attrition on both the start-headcount and average-headcount methods, plus the annualised rate.

Open calculator
Live

Capacity Planning Calculator

Model monthly FTE requirement from forecast volume, AHT, working days, shift length, target occupancy and shrinkage.

Open calculator
Trending

Volume Forecasting Toolkit

Compare nine forecasting methods on your own history, pick the best fit by MAPE backtest, then break the forecast down to day of week and interval.

Open calculator
Trending

Shift and Break Optimizer

Place shift start times, breaks and lunches with a local search optimiser, then see coverage, break shrinkage and projected service level by interval.

Open calculator