Estimated maintenance calories per day
| Group | Sedentary | Moderately active | Active |
|---|---|---|---|
| Women (19–30) | ~2,000 | ~2,100 | ~2,400 |
| Women (31–50) | ~1,800 | ~2,000 | ~2,200 |
| Women (51+) | ~1,600 | ~1,800 | ~2,000 |
| Men (19–30) | ~2,400 | ~2,700 | ~3,000 |
| Men (31–50) | ~2,200 | ~2,500 | ~2,900 |
| Men (51+) | ~2,000 | ~2,300 | ~2,600 |
What the activity levels mean
The labels are vaguer than they look, and picking the wrong column is the most common way people misread this chart.
- Sedentary — daily living only. A desk job, no structured exercise, no physically demanding commute. This describes more people than expect it to.
- Moderately active — the equivalent of walking a few kilometres a day beyond normal activity, or training three to five times a week at moderate intensity.
- Active — daily training, or a job that keeps you on your feet and moving for most of the day.
Notice from the chart that the gap between sedentary and active within one group — 400 kcal for younger women, 600 for younger men — is often larger than the gap between age bands. How much you move is doing more work here than how old you are.
Why your own number will differ
These are averages across large populations, and there is substantial individual variation around them. The main sources of that variation:
- Body size and composition. A larger body costs more to run, and lean mass is metabolically more expensive than fat mass. Two people of the same weight with different muscle mass have different requirements.
- Non-exercise activity. Fidgeting, standing, pacing, gesturing — collectively NEAT — varies enormously between individuals and can account for a few hundred calories a day. It also tends to fall quietly when you diet, which is part of why weight loss slows.
- Genetics and hormonal factors. Thyroid function in particular has a direct effect on resting expenditure.
- Adaptation. Sustained dieting reduces energy expenditure by more than the weight loss alone predicts.
A well-validated predictive equation such as Mifflin-St Jeor is typically accurate to within about 10% for most people, which at 2,400 kcal is a spread of nearly 500 calories. That is a meaningful margin, and it is why the only reliable way to find your maintenance level is to eat at a consistent estimate for two to three weeks and see which way your weight actually trends.
Using the chart for a goal
Find your row, pick your activity column honestly, and treat the result as a hypothesis to test.
- To lose fat: subtract roughly 300–500 kcal. That produces a loss of about 0.3–0.5 kg per week for most people. A larger deficit does produce faster loss initially, but costs disproportionately more muscle, energy, and adherence.
- To maintain: eat around the figure and adjust based on the trend over a month.
- To build muscle: add roughly 200–400 kcal alongside resistance training. Larger surpluses mostly add fat.
The calorie deficit calculator turns a target rate of loss into a daily number, and the macro calculator splits whichever figure you land on into protein, carbohydrate and fat.
The 3,500-calorie rule is wrong
The familiar rule that a 3,500 kcal deficit equals a pound of fat lost assumes the relationship stays linear forever. It does not. As you lose weight, you become a smaller body that costs less to move and to maintain, and expenditure falls accordingly — so a fixed deficit produces progressively smaller losses and eventually none at all. Modelling work published in the Lancet describes this decay properly: a change in intake leads to a new, lower steady weight approached gradually over roughly a year, not to indefinite linear loss.
Practically, this means you should expect to recalculate. A target that worked at the start of a fat-loss phase will be too high after 10 kg, and the plateau people interpret as a broken metabolism is usually just arithmetic catching up.
Calories are not the whole story
Energy balance determines your weight. It does not determine your health, your body composition, or how you feel while getting there. Two diets at identical calories — one built on protein, vegetables, fruit, fibre, and whole foods, the other on refined snacks — produce very different outcomes for satiety, muscle retention, blood markers, and whether you can actually stick with it for six months.
Protein deserves particular attention in a deficit, because it protects lean mass and is the most satiating of the three macronutrients. Get that right and the calorie target largely takes care of itself.