Sprint Velocity Calculator
Calcola la velocità media del team, la deviazione standard e prevedi la capacità per i prossimi sprint agile.
Dati Sprint
| Sprint | Story Points | Azioni |
|---|---|---|
Risultati
Story Points per Sprint
Previsione Sprint Futuri
Come funziona la Sprint Velocity
Media (Mean Velocity)
La somma degli story point completati divisa per il numero di sprint. Usata come baseline per il planning futuro.
Deviazione Standard
Misura la variabilità della velocità. Una deviazione bassa indica un team stabile; alta indica imprevedibilità.
Intervallo di Confidenza 95%
Intervallo nel quale ci si aspetta che la velocità del prossimo sprint ricada con probabilità 95%, calcolato con distribuzione t.
Previsione Sprint
Le previsioni usano la media recente (ultimi 3 sprint) e la media storica come blend, riducendo l'impatto di outlier lontani nel tempo.
Come utilizzare Sprint Velocity Calculator
Insert completed story points for each past sprint
Add each historical sprint with the actual number of story points completed (not estimated). At least 2 sprints are required to calculate statistics.
Configure Forecast
Set future sprint goals - The calculator uses recent and historical averages to estimate upcoming sprint velocity.
Read statistical results
The tool calculates mean, standard deviation, median, minimum/maximum, and the 95% confidence interval of team velocity.
Use forecasting for next sprint planning
Use the average value or confidence interval as a reference to estimate how many story points your team can commit to completing in the next sprint.
Suggerimenti
- Only count completed user stories at 100%, never partial work.
- If the team changes composition significantly, historical velocity loses meaning: reset the series and start measuring from the first sprint with the new composition.
- Never compare velocity between different teams: it depends on how each team estimates story points, not an absolute measure of productivity.
Domande frequenti
What is sprint velocity in Scrum?
Sprint velocity is the average number of story points a Scrum team completes per sprint. It's calculated by summing up the story points of completed user stories (not just started) in each sprint and averaging it over multiple iterations. It's an empirical team metric, not a target to enforce.
How is standard deviation of velocity calculated and what does it mean?
Standard deviation measures how sprint velocity deviates from the mean. It's calculated as the square root of the variance (sum of squared deviations from the mean, divided by n-1). A low standard deviation indicates a stable and predictable team; a high standard deviation signals variability due to imprecise estimates or frequent scope changes.
What is the 95% confidence interval shown in the result?
This is the range of values within which one expects the velocity of the next sprint to fall with a 95% probability, calculated using an approximation of the Student's t-distribution (margin of error = t-value multiplied by standard deviation, divided by the square root of the number of sprints). The more historical sprints you add, the narrower and more reliable the interval becomes.
How many historical sprints do you need for a reliable forecast?
The calculator works from 2 sprints up, but for a statistically robust estimate, at least 6-8 sprints are recommended. With less data, the forecast is heavily affected by individual outliers, such as an interrupted sprint due to holidays or an emergency.
Why is predicting the next sprints not simply historical averages?
The calculator weighs the average of the last 3 sprints together with the overall historical average, giving more weight to recent team trend (onboarding, composition change, process maturity) while avoiding excessive sensitivity to an individual anomalous sprint.