Maintenance Calorie Calculator

BMR = 10 × kg + 6.25 × cm − 5 × age + (5 male, −161 female) · Calories to maintain weight = BMR × activity factor · Gap = now − at target

kg

Body weight — the one you are at now, and the one you are aiming for (kg)

cm

Height (cm)

age

Age in whole years

activity factor

The multiplier for how active you are

gap

The daily calorie gap between maintaining now and maintaining at your target (kcal)

weekly change

What that gap implies for weekly weight change, at roughly 7,700 kcal per kilogram (kg)

Use it when you have a goal weight and want to know what eating looks like once you get there — before you start, so the target is a plan rather than a number. The main figure is the one to aim at after the change; the second is what your current body burns; the daily calorie gap between them is what you would be cutting right now. If you are already at the weight you want to keep, this page's second figure is the one you need, and it agrees exactly with what the TDEE calculator gives for the same body.

1. Man, 30, 175 cm, 80 kg aiming for 70 kg, moderately active

   1. BMR at 80 kg: 10 × 80 + 6.25 × 175 − 5 × 30 + 5 = 1748.75
   2. Maintenance now: 1748.75 × 1.55 = 2710.56, rounded to 2711 kcal
   3. BMR at 70 kg: 10 × 70 + 6.25 × 175 − 5 × 30 + 5 = 1648.75
   4. Maintenance at 70 kg: 1648.75 × 1.55 = 2555.56, rounded to 2556 kcal
   5. Gap: 2711 − 2556 = 155 kcal a day
   6. Weekly change: 155 × 7 ÷ 7700 = 0.14 kg a week, which the page reads as a steady pace

   Ten kilograms cost 155 kcal a day at this height, age and activity level — about one and a half tablespoons of oil. That is the number worth sitting with: a deficit that big is easy to erase by accident, and it is also why weight loss slows as it goes. Eating at 2556 kcal from the start would be eating at maintenance for a body that does not exist yet, which is the mistake this page exists to make visible.

2. Man, 30, 175 cm, 120 kg aiming for 60 kg, very active

   1. BMR at 120 kg: 10 × 120 + 6.25 × 175 − 5 × 30 + 5 = 2148.75
   2. Maintenance now: 2148.75 × 1.9 = 4082.63, rounded to 4083 kcal
   3. BMR at 60 kg: 10 × 60 + 6.25 × 175 − 5 × 30 + 5 = 1548.75
   4. Maintenance at 60 kg: 1548.75 × 1.9 = 2942.63, rounded to 2943 kcal
   5. Gap: 4083 − 2943 = 1140 kcal a day
   6. Weekly change: 1140 × 7 ÷ 7700 = 1.04 kg a week, faster than the usual advice

   The badge warns here, and what it is saying is worth reading carefully: the gap is not wrong, but one that size cannot be held for the whole journey — it would mean eating 1140 kcal below what the current body burns. What the page is pointing at is the shape of the plan rather than the number: split a goal that far away into stages, so the gap stays near 300 to 500 kcal and each stage ends somewhere you can actually stay. At 1.04 kg a week the gap is also the reason the target weight must move as you go: the same 2943 kcal that maintains 60 kg is a deficit at 120 kg and maintenance at 60 kg.

The activity multiplier describes a whole day, not a training session, and choosing it is the largest source of error on the page — being wrong by one step moves the answer by hundreds of kilocalories. The equation behind the resting figure was fitted to groups of adults and can be off by a few percent for any individual, which at these numbers is more than the total gap in the first example. The gap is read as weight change at roughly 7,700 kcal per kilogram, an approximation whose error runs the other way here than on the deficit calculator: there the pace is chosen and the deficit follows, here the deficit falls out of two weights and the pace is what is being read back. The estimate also assumes the activity level stays the same as weight comes off, and it usually does not — a lighter body is usually moved less. Nothing here accounts for a change in muscle mass, which changes the resting figure at the same body weight, or for the water and glycogen shifts that make early weeks move faster than any calorie gap explains.

How many calories to stay at my goal weight?

The number depends on the goal weight itself, because a lighter body burns less at rest and moves less for the same activity. A 70 kg man of 30 at 175 cm who is moderately active maintains that weight on about 2556 kcal; the same man at 80 kg maintains on about 2711. That is why this page asks for the weight twice — once for the body you have and once for the one you are aiming at.

Why are there two calorie figures instead of one?

Because the answer to the question changes as you change. The first figure is the calories to maintain weight at your target; the second is what your current body burns, which is the same number the TDEE calculator gives. The daily calorie gap between them is what you would eat below today, and it is the part that actually tells you whether your plan is realistic — a gap of 155 kcal and a gap of 1140 kcal are both arithmetic, and only one of them is something you can hold.

Is this the same as the TDEE calculator?

The second figure is: maintaining your current weight is what TDEE means, and both pages use the same equation and the same activity multipliers, so they always agree. What is different is what they ask for and what they lead with. TDEE takes your body as it is; this page takes your body as you want it, and leads with the maintenance figure at the target rather than at the present.

How fast should I lose weight?

Common advice is around half a kilogram to one kilogram a week, which is why the badge changes tone above that. The limit is not a physiological wall — a weekly weight change is the calorie deficit divided by roughly 7,700 kcal per kilogram — but a pace is only useful if it can be held for months, and a large deficit usually cannot. If the badge says the pace is fast, the answer is not to eat less; it is to move the target closer and take it in stages.

What is a good calorie deficit per day?

Something in the region of 300 to 500 kcal a day, which comes out at roughly 0.3 to 0.5 kg a week. The size that suits you depends on how much there is to lose and how much activity the plan has to support; a smaller deficit is slower but leaves more room for protein and training. The page does not set the deficit for you — it reads the deficit out of the two weights you entered and tells you what pace that implies.

Will my maintenance calories change as I lose weight?

Yes, and that is the whole reason the two figures on this page differ. Every kilogram of body weight moves the resting figure by about 10 kcal a day before activity is applied, and more than that once the activity multiplier is applied. The practical consequence is that a plan set up at the start is too generous by the end: either the target moves down as you go, or the pace slows on its own, and both are the same arithmetic seen from two sides.

• A new predictive equation for resting energy expenditure in healthy individuals — Mifflin MD, St Jeor ST, et al. — American Journal of Clinical Nutrition, 1990
• Losing weight — healthy weight growth — Centers for Disease Control and Prevention
• Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) — Institute of Medicine — National Academies Press, 2005