Calorie Calculator

A calorie target tells you how much to eat in a day to move toward a specific goal — losing weight, maintaining it, or gaining it — rather than just showing your maintenance number the way TDEE Calculator does. This calculator takes your Total Daily Energy Expenditure and applies a flat, standard adjustment on top of it: subtract 500 calories a day to lose weight, add 500 to gain, or leave it unchanged to maintain.

That ±500 kcal/day figure comes from the widely used "3,500 kcal ≈ 1 lb of body fat" rule of thumb: 500 kcal/day × 7 days ≈ 3,500 kcal/week, which is approximately one pound of weight change per week. It's a population-average approximation rather than a guarantee for any one person — real weight change is influenced by water retention, sleep, hormones, and how consistently the target is actually followed — but it's the same convention used across most consumer calorie calculators.

Very low calorie targets can fall below what's generally considered a safe daily minimum. If your result lands under roughly 1,200 calories/day (women) or 1,500 calories/day (men), this tool flags it directly on the result — without changing the number itself — as a signal to check with a healthcare provider before following it. Recalculate periodically as your weight, activity, or goal changes, since the target is only as accurate as the stats behind it.

A worked example

Take a 35-year-old, 80 kg, 180 cm man, moderately active, with a TDEE of 2,720 calories a day. To lose weight, this calculator subtracts the standard 500 kcal/day: 2,720 − 500 = 2,220 calories a day. To gain weight, it would add 500 instead: 2,720 + 500 = 3,220. To maintain, the target is simply the TDEE itself, unchanged at 2,720.

A common misconception

The "500 calories = 1 lb a week" math looks precise, but it's a simplification the research behind the NIH Body Weight Planner has specifically pushed back on. A 2011 analysis by Kevin Hall and colleagues found that the flat 3,500-kcal-per-pound rule ignores how resting metabolism and activity-related energy expenditure both shift as the body loses weight, which is why the rule tends to overpredict real-world weight loss — a sustained 500 kcal/day deficit rarely produces a clean, linear pound-a-week loss all the way to goal. The rule remains useful as a simple starting estimate, which is why this calculator and most others still use it, but it's a rule of thumb, not a physical law.

Where a flat adjustment falls short

The same metabolic adaptation covered on TDEE Calculator's page applies directly here: as you lose weight, your TDEE — and therefore the real deficit a fixed intake creates — shrinks along with it, which is part of why weight loss commonly stalls even when intake hasn't changed. A calorie target calculated once from your starting stats will drift out of date the more weight you lose or gain, and very aggressive deficits (especially combined with high activity levels) can push a target below what's considered a safe daily minimum, which this tool flags directly on the result.

How to use your target

Use the number as a starting point, then adjust based on results rather than sticking to it indefinitely without checking in. If your weight isn't moving the way your goal predicts after 2–3 weeks of consistent eating near the target, that's a signal to recalculate — using your updated current weight — rather than a sign you're doing something wrong. Prioritize consistency over precision: a target followed loosely most days beats a precise number followed perfectly for a week and abandoned the next.

Flat-adjustment vs. dynamic models

This calculator's ±500 kcal/day approach is a static, one-time calculation — simple to compute and explain, which is why it's the convention nearly every consumer calorie calculator uses. More sophisticated tools, like the NIH-backed Body Weight Planner, use a dynamic model that continuously adjusts its prediction as your weight and metabolism change over the course of a diet, generally producing more realistic long-term projections. For a single starting estimate, the static approach here is a reasonable, well-established convention; for tracking a multi-month weight-change plan in detail, a dynamic model will track reality more closely.