Open-source & free tools for contact centre planners

The tools you can use today without a procurement conversation — browser calculators, spreadsheet templates and add-ins, code-level libraries for the Python- or R-curious, and open datasets. Every external link verified as live and genuinely free. Editorial; nobody listed has paid for placement. Last reviewed: June 2026.

The honest caveat, up front. Free tools shift the maintenance burden to you. There’s no support desk, no SLA, and no one to ring when a formula misbehaves at month-end — you (or whoever inherits your spreadsheet) are the support desk. And a library is not a planning process: statsforecast will fit a thousand models in seconds, but it won’t tell you which forecast to defend in the capacity review. Free tools are excellent for learning, validating, and bridging the gap before a proper WFM system — they’re not a substitute for the discipline around them.

Ours — free tools on this site

Yes, we’re listing ourselves first. They’re free, browser-based or Excel, no sign-up, no email gate — and we’d be daft to send you elsewhere for things we’ve already built.

Planning calculators (28)

Browser-based and instant: Erlang B, C, A and X, shrinkage, FTE budget, intraday profiles, shift coverage, ramp-up, QA sample size, cost-of-attrition and more. What a planner uses them for: sanity-checking a requirement before it goes anywhere near a business case. Ours Free Browser

Downloadable templates (13)

Nine Excel workbooks — shrinkage tracker, forecast accuracy log, capacity plan, schedule coverage, QA scorecard among them — plus four one-page PDF cheat sheets. All live formulas, CC-BY licensed, no sign-up. The starter kit for an operation that runs on spreadsheets. Ours Free Excel/PDF

Look-up tables

Pre-computed staffing answers — agents required across common volume, AHT and service-level combinations — for when you need a number in a meeting and a calculator is one tab too many. Ours Free Reference

Spreadsheet-level — free Erlang calculators & Excel tools

No code required. The long-standing free calculators and templates from sources planners already trust. Watch your IT macro policy — several of these use VBA.

Call Centre Helper — Excel Erlang Calculator

The most widely used free Erlang workbook in the industry, now at version 6 with maximum-occupancy and shrinkage inputs. Macro-based, so IT policy permitting; the unlock code comes free with their newsletter. What a planner uses it for: requirement calculations inside their own workbooks via the AgentsRequired and ServiceLevel functions. Free Excel Macros

Call Centre Helper — online Erlang calculator

The browser version of the same engine, with abandons and a day planner, and no macro headaches. Handles larger agent counts than the spreadsheet. What a planner uses it for: a quick second opinion when two tools disagree. Free Browser

Call Centre Helper — monthly forecasting Excel template

A free monthly forecasting spreadsheet built around seasonal decomposition of historical volumes. What a planner uses it for: a first structured forecast when the alternative is finger-in-the-air. Compare with our own forecasting methods workbook, which works the methods side by side. Free Excel

Westbay Engineers — free online Erlang calculators

The originals — online since 1996. Eight calculators covering Erlang B, Erlang C, a combined call-centre calculator (agents and trunks over a five-hour window), Engset, and VoIP bandwidth. Their Excel add-ins are paid; the online calculators are genuinely free. What a planner uses them for: trunk and line sizing, which most WFM tools ignore. Free Browser

Abstract Micro Systems — Erlang Library for Excel

A free Excel add-in with fifteen Erlang B and C worksheet functions, no registration. Honest caveat: it’s old — documentation references Excel 2003–2013 and it hasn’t seen recent maintenance, though the maths doesn’t age. Test on your Excel version before relying on it. Free Excel add-in Dated

Code-level — Python libraries

For the Python-curious planner. All open-source, all installable with pip. The trade-off: enormous power, zero hand-holding, and version upgrades become your problem.

statsmodels

The standard statistical library for Python; its time-series module covers ARIMA, exponential smoothing (Holt-Winters), and seasonal decomposition. What a planner uses it for: a defensible classical forecast with full control over seasonality and trend — the closest code equivalent to what your WFM tool does under the bonnet. Open source Python Forecasting

Nixtla statsforecast

Very fast implementations of AutoARIMA, AutoETS, MSTL and Theta, designed to fit many series at once. Actively maintained (part of the wider open-source Nixtla ecosystem). What a planner uses it for: forecasting dozens of queues or skill groups in one run, then benchmarking the WFM tool’s forecast against it. Open source Python Forecasting

Prophet (Meta)

The approachable one: handles multiple seasonalities, holidays and outliers with sensible defaults, still maintained (v1.3.0, January 2026). No longer the automatic first choice — statsforecast often beats it on accuracy and speed — but it remains the gentlest on-ramp. What a planner uses it for: a first daily-volume forecast with holiday effects, in an afternoon. Open source Python Forecasting

sktime

A scikit-learn-style framework that wraps statsmodels, Prophet, pmdarima and more behind one consistent API, with proper backtesting (rolling-origin cross-validation) built in. What a planner uses it for: comparing forecasting methods fairly — the evaluation discipline matters more than any single model. Open source Python Framework

pyworkforce

The one library written specifically for our problem: Erlang C requirement calculations plus shift-assignment optimisation on top of Google OR-Tools. Honest caveat: a small single-maintainer project with sparse releases — read the source and validate against a known calculator before trusting it. What a planner uses it for: scripting requirement-to-shift studies that would be painful in Excel. Open source Python WFM-specific

Google OR-Tools (CP-SAT)

Google’s open-source optimisation suite (Apache-licensed); the CP-SAT solver handles employee scheduling and rostering with hard and soft constraints, and the documentation includes worked shift-scheduling examples. What a planner uses it for: prototyping schedule optimisation to understand what the WFM vendor’s “optimiser” is actually doing — this is industrial-strength, not a weekend toy. Open source Python/C++ Scheduling

Code-level — R

The R forecasting ecosystem is arguably stronger than Python’s for classical methods, largely thanks to one academic group — and the textbook is free.

forecast (R package)

Rob Hyndman’s classic package — auto.arima() and ets() are the reference implementations that many commercial tools quietly imitate. Stable and battle-tested. What a planner uses it for: the benchmark forecast everything else has to beat. Open source R Forecasting

fable (tidyverts)

The modern successor to forecast, rebuilt for the tidyverse: fit several models across many series in one pipeline, with consistent accuracy evaluation. What a planner uses it for: the same multi-queue benchmarking job as statsforecast, in R. Open source R Forecasting

Forecasting: Principles and Practice (3rd ed.)

Hyndman & Athanasopoulos’s textbook, free to read online in full, with examples in fable. Not a tool, but the best free education in forecasting a planner can get — read the chapters on exponential smoothing and evaluation even if you never write a line of R. Free Book R

Open data

Real contact centre data you can practise on — rarer than you’d think, because almost nobody publishes theirs.

Technion SEE Lab data repository

The academic gold standard: transaction-level call centre event logs, free to use with acknowledgement. Includes a small Israeli bank call centre (~15 agents) and a large US bank centre (~1,000 agents). What a planner uses it for: testing forecasting and queueing methods on real arrival, handle-time and abandonment data before pointing them at their own. Free Dataset Academic

What we deliberately left out

A few things you’ll find in other “free tools” round-ups that didn’t make this list: vendor calculators that exist mainly to harvest your email address; “community editions” whose free tier is a time-limited trial in disguise; abandoned GitHub projects with promising names and no commits in years; and Excel add-ins we couldn’t verify as still downloadable. If something here stops being free or stops working, tell us in the discussion on LinkedIn — we review this page with each quarterly pass.

Spotted a genuinely free tool we’ve missed? Tell us in the discussion on LinkedIn.