A burndown chart is the simplest honest signal a sprint produces. It shows how much work remains versus how much time is left — and the gap between those two lines tells you whether the team is on track or heading for trouble.
What a burndown chart shows
The vertical axis shows remaining work (usually story points or task count). The horizontal axis shows time (sprint days). A diagonal ideal line runs from the total work at sprint start to zero on the last day. The actual line tracks real progress.
When the actual line runs above the ideal line, the team is behind. When it runs below, the team is ahead. When it goes flat or rises, work was added or something is blocked.
How to read the common shapes
Flat sections: no progress for several days. Look for blocked work, unclear acceptance criteria, or unresolved dependencies.
Steep drops: large chunks of work completed quickly. Often good — but verify that stories were truly done and not just marked done.
Rising sections: scope was added mid-sprint. This is fine if deliberate; a problem if it happens by default every sprint.
Never reaches zero: the team consistently over-commits. Use velocity data to right-size the next sprint.
Burndown chart vs velocity chart
A burndown chart is sprint-level: it shows this sprint's trajectory. A velocity chart is release-level: it shows how much the team completes per sprint over time. You need both. Burndown catches problems inside a sprint; velocity catches planning problems across sprints.
When burndown charts lie
Burndown charts are only as honest as the estimates behind them. If stories are not updated daily, the chart goes flat and then drops in a cliff when someone bulk-updates their tasks. If estimates are inflated to look safe, the chart looks ahead even when the team is struggling.
Use the chart as a conversation starter, not a performance metric.
How to create one
You can use our free burndown chart generator to produce one instantly from your sprint data, or track it manually in a spreadsheet if your team prefers low-ceremony tooling.
Common questions
Should the chart hit zero exactly? No. Hitting zero means the team estimated perfectly — unusual. The goal is learning, not precision.
Who updates it? In Scrum, the team. The Scrum Master often facilitates, but every developer updates their own tasks.
What if we use Kanban? Use a cumulative flow diagram instead. Burndown charts assume a fixed sprint backlog, which Kanban does not have.
Related reading: Burndown vs burnup charts · Burndown chart best practices · Build one in Excel.