Calorie Deficit Calculator

Standard (−500/day, about a pound a week) is the default for good reason: meaningful progress that most people can sustain without their training, sleep, and mood degrading. Gentle (−250) suits people with less to lose or who want to protect gym performance; aggressive (−750) is defensible short-term with plenty to lose. The meta-rule the research keeps confirming: the deficit you can hold for months beats the bigger one you abandon in week three.

Because below those floors it becomes genuinely hard to get adequate protein and micronutrients or to fuel normal activity, and prolonged very-low-calorie eating belongs under medical supervision, not a web calculator. If the cap kicks in, it means the requested deficit is too large for your maintenance level — the honest fixes are a smaller deficit, more daily movement (which raises the maintenance number), or accepting a later goal date.

It's a planning estimate built on the ~3,500-calories-per-pound approximation, and it drifts optimistic over months for known reasons: metabolism adapts downward somewhat as you lose, and the maintenance estimate itself carries ±10%. Expect the real timeline to run 10–20% longer. The date's real job is making the pace concrete — what matters in practice is still being on the plan in week six, not hitting a calendar day.

Almost certainly not. Day-to-day scale movement is dominated by water: sodium, carbohydrate intake (each gram of stored glycogen holds ~3g of water), training inflammation, and digestion can swing several pounds with zero fat change. A real deficit shows up in the trend, not the days — weigh under consistent conditions, average each week, and compare 2-week averages. If the 2-week average is flat for a month, then adjust the target down by 100–200.