Sprint Velocity Calculator
Predicts your team's next sprint velocity by averaging the last three sprints and adjusting for team size and sprint length. Use it during sprint planning to set a realistic story-point commitment.
About this calculator
Sprint velocity is the average rate at which a team completes story points, used to forecast how much work fits in a future sprint. This calculator uses the formula: Velocity = round(((sprint1Points + sprint2Points + sprint3Points) / 3) × (1 + (teamSize − 5) × 0.05) × (sprintLength / 2)). The three-sprint average smooths out one-off anomalies like holidays or unplanned outages. The team-size adjustment adds 5% capacity for each member above a baseline team of 5, reflecting that larger teams can parallelize work — though this effect diminishes in practice beyond ~9 members. The sprint length multiplier scales output proportionally to the length of the sprint in weeks, since a 4-week sprint should yield roughly twice the output of a 2-week sprint.
How to use
A team of 7 completed 34, 38, and 36 story points in their last three sprints, running 2-week sprints. Calculate: average = (34 + 38 + 36) / 3 = 36. Team-size adjustment = 1 + (7 − 5) × 0.05 = 1.10. Sprint-length multiplier = 2 / 2 = 1.0. Velocity = round(36 × 1.10 × 1.0) = round(39.6) = 40 story points. The team should plan their next sprint around 40 points, leaving a small buffer for uncertainty or unplanned support work.
Frequently asked questions
How many sprints of historical data do I need for an accurate velocity estimate?
Three sprints is the practical minimum for a meaningful average, and this calculator uses exactly that to balance recency with stability. Fewer than three sprints introduces high variance — a single holiday week or onboarding event can skew the result dramatically. Five to six sprints is ideal for stable teams because it captures seasonal variation and smooths out individual anomalies. For brand-new teams with no history, use a planning poker session to estimate the first sprint and treat the result as provisional until three data points are available.
Why does team size affect sprint velocity and how is the adjustment calculated?
Larger teams can work on more tasks in parallel, which increases raw throughput — but not linearly, because coordination overhead grows with team size. The formula uses a 5% increment per member above a baseline of 5, meaning a team of 8 gets a 15% boost over the baseline. This is a deliberate simplification: in reality, productivity per person often decreases as teams grow past 7–9 members due to communication overhead described by Brooks's Law. Use the size adjustment as a rough guide, and validate it against your team's own historical data whenever possible.
What is the difference between sprint velocity and sprint capacity and when should I use each?
Velocity is a measure of historical output in story points — what the team actually delivered. Capacity is a forward-looking measure of available person-hours in the upcoming sprint, accounting for holidays, part-time members, and planned absences. Velocity is the right planning tool when your team has stable membership and consistent story sizing, because it implicitly captures all those factors from past sprints. Capacity planning is better when significant changes are expected — a team member leaving, an unusually short sprint, or a major company holiday — because velocity alone won't reflect those differences. Best practice is to use velocity as your baseline and then adjust down for known capacity reductions.