Cycle time and work in progress calculator
Little’s law says cycle time equals work in progress divided by throughput. Starting more work at once does not get it finished sooner — it makes every item take proportionally longer.
Cycle time and work in progress, step by step
The law holds for any stable queue, which makes it the most reliable arithmetic in software delivery. A team finishing 10 items a week with 20 items open has a two-week cycle time. Open 40 items and the cycle time becomes four weeks, with exactly the same output.
Because throughput is bounded by the team and not by how much is started, the only lever that shortens cycle time is reducing work in progress. That is the whole case for a WIP limit, and it is arithmetic rather than methodology preference.
Where this number misleads you
Little’s law describes a stable system measured over a long enough window. It says nothing about a single ticket, and it breaks down when arrivals are wildly uneven or the team composition changes mid-period. Use it for planning averages and expectations, never to predict when one particular item will be done.
Questions people ask
What is Little’s law in agile?
Cycle time = work in progress ÷ throughput. For a team completing 10 items a week with 20 in progress, average cycle time is two weeks. It holds for any stable queue, which is why limiting work in progress shortens delivery time without changing anything else.
Does limiting WIP really make work faster?
It makes each item finish sooner, which is usually what people mean. Throughput is set by the team’s capacity, not by how many things are open, so halving work in progress halves average cycle time while total output stays the same — and finished work ships, while work in progress does not.
How do I measure throughput?
Count items completed per unit of time over several periods — items per week is the usual choice. Use completed items rather than story points: Little’s law works on counts, and item counts avoid the estimation argument entirely while being just as predictive in practice.
When one number is not the job
This page works out one number. PikoPM’s Capacity planner plans a real team — holidays, part-timers, three countries — instead of one number at a time.
Open Capacity planner — it needs an account, and the Free plan covers it.