Calorie Deficit Tracker (7-Day)

Classical static rule from Wishnofsky 1958 — 1 lb of body fat stores roughly 3,500 kcal. Modern research (Hall et al. 2011) shows fat loss adapts over time, so the rule is most accurate over the first 6 to 12 weeks. We use it for projection because it is the cleanest mental model for daily decisions.

If you don't already know it, use our free TDEE calculator. The default 2,200 is a US-average ballpark. After 2 weeks of consistent tracking, you can back-calculate your real TDEE from intake and weight change.

The math is correct under the assumption you stay compliant. Real-world week 1 weight loss is often higher (glycogen + water flush) then settles to ~0.5 to 1 lb per week. If you see less, your TDEE is probably overestimated. If much more, possibly underestimated or you cut very aggressively.

No — the data lives in this browser tab's localStorage only. Clearing browser data or using incognito will erase it. For real cross-device tracking with photo logging, Zealova does that in the app.

Day-to-day weight is dominated by water, sodium, glycogen, menstrual cycle, and bowel content. The signal is the 7-day rolling average, not the daily reading. Stay the course; the trend line is what matters.

Every day. Weekend overshoots are the #1 reason people don't lose weight on what looks like a clean week. The weekly average is what drives loss, and skipping weekend logging hides 30% of the data.

The tracker still records it — the deficit goes negative, which lowers your weekly total. That's how it should work. One day over does not break a week; consistent weekly average is what counts. Don't cut harder the next day to compensate, that compounds adherence problems.