What are maintenance calories, and how do you find yours?
Maintenance calories is the amount you can eat in a day without gaining or losing weight. Eat below it and you lose; above it and you gain. Every deficit plan is defined relative to this one number, which makes it the most useful figure in weight management — and the one most people never establish properly.
It is the same thing as TDEE, total daily energy expenditure. Two names, one number.
What it is made of
Maintenance is the sum of four things:
| Component | Share of the day | Can you change it? |
|---|---|---|
| Basal metabolic rate | 60–70% | Slowly, via lean mass |
| Non-exercise activity | 15–30% | Yes, and often unconsciously |
| Digestion (thermic effect) | ~10% | Barely |
| Deliberate exercise | 0–15% | Yes, but it is the smallest slice |
The striking part is the last row — there is more on this in how many calories you should burn in a day. Exercise is usually the smallest contributor, while the thing you do nothing for — simply being alive — is by far the largest. That is why “I’ll just train it off” works less well than people expect.
Estimating it
Start from BMR via Mifflin–St Jeor, then multiply by an activity factor:
| Lifestyle | Multiplier |
|---|---|
| Desk job, little movement | 1.2 |
| Light activity, 1–3 days training | 1.375 |
| Moderate, 3–5 days | 1.55 |
| Heavy, 6–7 days | 1.725 |
| Physical job or two sessions a day | 1.9 |
A 35-year-old man at 82 kg and 178 cm — 181 lb and 5’10” — has a BMR near 1,760 kcal. Lightly active,
his maintenance is roughly 1,760 × 1.375 ≈ 2,420 kcal.
That is an estimate stacked on an estimate. The BMR formula carries about ±10%, and the activity multiplier is a blunt instrument — the gap between 1.375 and 1.55 is nearly 300 kcal, and most people genuinely cannot tell which describes them.
Measuring it instead
The estimate is a starting point. Your own data gives you the real number, and it only takes a few weeks:
- Eat roughly consistently for two to three weeks — no deliberate deficit.
- Record intake as accurately as you can stand.
- Weigh yourself daily, same conditions, and take the weekly average. Day to day noise is mostly water and is not signal.
- Compare week-one average to week-three average.
Then adjust:
- Weight steady → you have found maintenance.
- Lost 0.5 kg (1 lb) over two weeks → you were running about 275 kcal/day under. Maintenance is your intake plus 275.
- Gained 0.5 kg (1 lb) over two weeks → maintenance is your intake minus 275.
The arithmetic uses the same constant as everything else: roughly 7,700 kcal per kilogram, 3,500 per pound, so 0.5 kg over 14 days is 3,850 ÷ 14 ≈ 275 kcal per day.
Why it moves
Maintenance is not a fixed property of you. It falls as you lose weight, because a smaller body costs less to run. It falls a little further through metabolic adaptation. And it drifts with how much you move — which itself tends to drop during a diet without you deciding anything.
Practically: recheck it every 5 kg (11 lb) or so. A maintenance figure from 10 kg (22 lb) ago is describing someone else.
Where the app sits
Caldown does not ask you to guess an activity multiplier. It takes resting energy from Apple Health where a Watch provides it, falls back to Mifflin–St Jeor where it does not, and adds the active energy actually recorded — so the maintenance figure underneath the countdown is measured rather than selected from a dropdown.
Once you have your maintenance, the calorie deficit guide covers turning it into a plan.
General information, not medical advice.