Maintenance Calorie Calculator

Maintenance calories are the intake at which your weight holds still: your basal metabolic rate, priced for the life you actually live. Enter your stats and your honest activity level, and this calculator returns your maintenance figure for the day — together with the standard gentle and standard cut targets and a lean gain target derived from it, ready to plan against.

BMR Times a Life

Maintenance — total daily energy expenditure, TDEE — decomposes into the basal metabolic rate (the cost of existing: organs, temperature, repair, priced by the Mifflin-St Jeor equation from weight, height, age and sex) multiplied by an activity factor that prices everything else, from desk stillness (×1.2) to the athlete-labourer's double life (×1.9). Men: BMR = 10 × kg + 6.25 × cm − 5 × age + 5; women: the same − 161. Mifflin (1990) remains the best-validated of the population equations against measured metabolism, which is why this hub's maintenance page is built on it while simpler cousins (the weight-multiplier "simple" intake page) serve as cross-checks. The calculator then does what maintenance numbers exist for: it prices the standard deviations from stillness — the gentle −250 and standard −500 cuts (roughly a quarter and a half kilo of fat a week in textbook terms) and the +300 lean gain — so the reader leaves with a plan's numbers, not just a fact.

Worked Example: 30 Years Old, 80 Kilos, Moderate Life

The defaults: BMR = 800 + 1,125 − 150 + 5 = 1,780 kcal, and at the moderate multiplier, maintenance = 2,759 kcal/day — cuts at 2,509 and 2,259, gain at 3,059. Read the BMR's composition for intuition: the weight term (800) and the height term (1,125) dominate, age's tax is 5 kcal a year of life, and the sex constant (166 kcal between the formulas at equal stats) prices the average body-composition difference the other health pages measure directly. The example's activity assumption is where honesty is tested: most people over-select their multiplier by one band (the "moderate" who trains twice is light, ×1.375, maintenance 2,448 — 300 kcal of phantom budget), and the calculator's note prescribes the only cure — the fortnight's weight trend, which no self-image can argue with.

The Error Bars Are Part of the Answer

Population equations carry individual error — measured BMRs scatter around Mifflin's predictions with a standard deviation near 10%, and activity multipliers are coarse bands over a continuous life — so a maintenance figure is a hypothesis with a few hundred calories of give, not a constant of nature. The scientific posture, printed in the widget's note, is calibration: eat at the computed figure for two to three weeks, weigh under consistent conditions, and adjust by the trend (a stable trend crowns the estimate; a drift of half a kilo a fortnight reprices maintenance by roughly 250 kcal/day in the drift's opposite direction). No page on this hub asks to be believed more faithfully than its reader's own scale, kept honestly for a fortnight; the formula's job is to give that experiment the best starting line physiology currently offers. Metabolic adaptation — the body's own counter-moves during long cuts, spending less as mass and movement shrink — means the calibrated number itself migrates; maintenance is a moving target that this page re-sights whenever the reader's stats or life change, which is precisely the habit its design trains.

NEAT: The Multiplier's Hidden Variable

Between the exercise bands lies the expenditure nobody schedules: non-exercise activity thermogenesis — steps, standing, fidgeting, occupational movement — which varies between desk-bound and on-feet lives by several hundred calories a day and explains most of the "same multiplier, different truth" the calibration step discovers. Two readers with identical stats and identical gym habits can hold maintenance figures 400 kcal apart on NEAT alone (the nurse versus the programmer), which is why the activity descriptions in the widget are written around the JOB and the steps, not the workouts. A step count is the practical NEAT meter: roughly 2,000 steps ≈ 1.5 km ≈ 60–100 kcal for most bodies, the exchange rate at which a walking habit reprices the multiplier without a single gym session.

When the Estimate and the Scale Disagree

Trust the scale's trend over any formula, including this one. The equation gives you a well-founded starting estimate; two honest weeks of weighing and logging turn it into your personal maintenance figure, which is the number worth planning a cut or a gain from.

Related Tools

More from the Health Calculators hub: the Carb Calculator — apportioning this total among the macros — and the Calorie Intake Calculator, the quick weight-based cross-check of this page's figure.

Frequently Asked Questions

Why Mifflin-St Jeor and not Harris-Benedict?

Validation: Mifflin's 1990 equation, fitted on measured indirect calorimetry, has repeatedly out-predicted the 1919 Harris-Benedict equations (and their 1984 revision) in modern adult samples — the Academy of Nutrition and Dietetics' evidence reviews name it the standard for non-obese adults. Harris-Benedict survives in older textbooks and in this site's archive pages; where the two disagree by a hundred-plus calories, Mifflin is the better bet, and the fortnight calibration of the section above settles what neither equation can. The calculator's formula is printed in full so the choice is auditable rather than branded.

Which activity level am I, honestly?

Count the week's structure, not its intentions: sedentary is a desk and under ~5,000 steps; light adds one to three genuine exercise sessions or a walking-rich job at 5–8k steps; moderate is three to five sessions or 8–12k daily steps with training most days; active and athlete describe lives most readers visit on holiday weeks only. The multipliers' spacing (each band roughly +0.15–0.2, worth 250–350 kcal on the worked example) punishes optimism directly in the budget — the commonest single cause of "the deficit that doesn't work" is a multiplier chosen by the person the reader is becoming rather than the one currently eating.

How fast should a cut proceed?

The textbook rates the widget prints: −250 kcal/day ≈ a quarter-kilo a week, −500 ≈ a half-kilo, with faster cuts risking lean-mass loss, adherence collapse and adaptive thermogenesis that slower cuts partly dodge. Percentage rules refine it (0.5–1% of body weight a week, the low end for lean dieters protecting muscle). The calculator prices the deficits; the choice among them is a temperament-and-deadline decision the worked example's framing deliberately leaves open, while warning — in its calibration note — that the scale's fortnight trend, not the plan's arithmetic, is the rate's true report.

Do I add back exercise calories on top?

Not if you selected an activity band that already includes the exercise — the multiplier IS the exercise, priced in — and double-counting wearables' burn estimates atop a moderate multiplier is the second commonest deficit-killer. Readers with genuinely irregular weeks (rest days at a desk, weekend epics) sometimes compute sedentary maintenance and add measured session burns day by day; that is a defensible alternative bookkeeping, provided the session figures are discounted (devices overstate by 20–30% in validation studies). One ledger, kept one way, is the rule; the calculator's multiplier method is the simpler ledger for regular lives.

Why does maintenance fall as I lose weight?

Three compounding reasons: a smaller body costs less to run (the weight term), less to move (every step carries less mass), and the adaptive component trims expenditure a little beyond both during active restriction. This is the plateau's arithmetic — a deficit computed at 90 kg evaporates by 80 kg — and the calculator is the repricing instrument: re-enter the new weight every few kilos and let the cut's target migrate honestly rather than concluding the body is broken. The same repricing, upward, explains the gain phase's creeping surplus requirement.

How do I maintain after a diet ends?

Recompute at the new weight (the calculator at your finished stats), then climb to that maintenance in steps of 100–150 kcal a week rather than in one leap — the scale will jump a kilo or two on glycogen and gut content regardless, which is physics, not fat — and hold the new figure under the same fortnight-trend surveillance that set it. Maintenance is a practice, not a graduation: the statistics of weight regain are largely the statistics of people who stopped measuring at the moment the measuring had finished its first job. This page, re-run quarterly, is the graduate programme.

Does age really cost only 5 kcal a year?

In the equation, yes — the −5 per year prices the AVERAGE decline of lean mass and organ metabolism across adulthood — but individuals diverge (the lifelong trainer's slope is gentler; the sedentary steeper), and the great metabolic study of 2021 (Pontzer's doubly-labelled-water consortium) found metabolism, adjusted for body composition, essentially flat from 20 to 60 and declining about 0.7% a year after — meaning much of the "middle-age slowdown" is composition and NEAT, both addressable. Enter your true age here; the calibration fortnight then corrects the population slope to your own.

Who was Mifflin, and what was St Jeor?

Mark Mifflin and Sachiko St Jeor led the University of Nevada team whose 1990 paper in the American Journal of Clinical Nutrition fitted resting metabolic rate on 498 healthy adults and produced the equation that displaced a seventy-year incumbent — a reminder that even physiology's constants get re-measured each generation. The calculator's use of their names is the citation the formula deserves; the equation's survival through thirty years of validation studies is the credential the page relies on.