A burndown chart is borrowed from agile project management. In sprint planning, it shows tasks remaining over time, sloping down to zero by the end of the sprint. CalBurndown points the same idea at your calorie budget.
If you've never seen one before, here's the entire chart explained.
The four lines
When you open today's view, the chart shows four things at once:
- Solid green — your actual remaining calorie budget over time. Drops when you eat, holds flat otherwise.
- Dashed gray (ideal) — straight line from your full budget at midnight to zero at next midnight. This is the "perfect pace" line.
- Dashed gray (projected) — from "now" to midnight, extrapolating your current pace forward.
- Vertical orange line — "now."
Stay above the dashed ideal line and you're on pace to hit your deficit. Below it, behind pace.
The headline number
The big number is calories left to eat today, based on what's actually happened. It's:
BMR (full day) + active so far − goal deficit − eaten
Note "active so far" — not projected. The headline is a conservative number: if you stopped moving right now, this is what you have left.
Next to it: +X if pace holds. That's the additional budget you'd earn by keeping today's movement pace for the rest of the day.
Examples
Headline 971, +207 if pace holds, 2pm:
You ate ~1,000 kcal so far, you've burned about 220 kcal of active calories on top of BMR, and your goal is a 250 kcal deficit. If you keep walking like you have been, you'll have ~1,178 kcal left by midnight. If you stop, ~971.
Headline reads "180 over budget":
You've eaten more than today's actual burn allows for your deficit. You can still earn it back — see buy-back tips or take a walk.
Why projected ≠ actual
Most apps roll all of your projected activity into one big number — and that number is dangerously optimistic at 9 a.m., when you've barely moved. CalBurndown splits them so:
- The big number is what's already locked in
- The small chip is the upside you're betting on
If you're the "I'll burn it off later" type, the big number keeps you honest. If you're moving consistently, the chip rewards it.
Status text
Below the headline:
- ahead of pace · room to spare — projected to hit your deficit comfortably
- on track for your deficit — projected within 5% of ideal
- behind pace · light dinner — eaten too much for current pace; can still recover with movement
- X kcal over · walk it off — projected over budget by midnight
Where to go next
- How to set a calorie deficit — the math behind the goal number
- How to calculate TDEE — how we estimate your total daily burn
- TDEE calibration — how the chart self-corrects over time