Sprint Forecast Calculator (Agile Velocity and Delivery Date)
How many sprints and weeks the rest of a backlog will take from your team's velocity, allowing for scope that keeps being added, with best and worst cases.
Results
The dashed line marks the value you entered.
What this tool does
Velocity-based forecasting divides the work left by the points the team usually finishes per sprint, which is as good a basis as most teams have. Two things make it more honest. First, scope creep: if 4 points arrive each sprint while you finish 30, you really burn 26, and a team that adds as many points as it delivers never finishes. Second, a range: using your fastest and slowest recent sprints gives a best and worst case, and the width of that range is the real uncertainty. Velocity is a planning aid for one team, not a measure of performance to compare between teams.
Formula
sprints = story points left ÷ (velocity − points added per sprint), rounded up · best and worst case from the fastest and slowest recent sprint
Variables
| Symbol | Meaning | Unit |
|---|---|---|
bl | Story points left to deliver | — |
v | Average velocity per sprint (points) | — |
vl | Slowest recent sprint (points) | — |
vh | Fastest recent sprint (points) | — |
ad | Points added to the backlog per sprint (scope growth) | — |
wk | Sprint length in weeks | — |
N | Sprints needed at average velocity | — |
W | That many weeks | — |
BC | Best case (fastest sprint speed) | — |
WC | Worst case (slowest sprint speed) | — |
ST | Will the backlog ever empty? | — |
Worked example
- Story points left to deliver240
- Average velocity per sprint (points)30
- Slowest recent sprint (points)24
- Fastest recent sprint (points)36
- Points added to the backlog per sprint (scope growth)4
- Sprint length in weeks2
- Sprints needed at average velocity10
- That many weeks20
- Best case (fastest sprint speed)8
- Worst case (slowest sprint speed)12
- Will the backlog ever empty?Yes, at the average velocity
Limitations
- The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
- The calculation runs at full precision and only the display is rounded. If you copy an intermediate value and retype it, small differences can appear.