Daily Calorie Needs
An estimate of how much energy your body uses in a day — at rest, and in total once activity is accounted for. Useful as a starting point to adjust from.
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Before you act on this
Four things worth knowing
It's an estimate, not a measurement
Predictive equations are typically accurate to within about 10% for most people — and further out for some. Two people with identical inputs can have genuinely different requirements.
Activity level is the biggest source of error
Most people overestimate how active they are. If your weight isn't moving the way the number predicts, the activity multiplier is usually the culprit.
Very low intakes need supervision
Sustained large deficits risk losing muscle alongside fat and can leave you short on nutrients. If the number here looks low to you, that's worth discussing rather than acting on.
Some situations need a different approach
Pregnancy, breastfeeding, eating disorders, kidney and liver disease, and several medications all change energy and nutrient requirements in ways this equation doesn't model.
How the calculation works
Resting metabolic rate is calculated with the Mifflin-St Jeor equation, which most dietetic bodies currently regard as the most accurate predictive formula for healthy adults:
Men: (10 × kg) + (6.25 × cm) − (5 × age) + 5
Women: (10 × kg) + (6.25 × cm) − (5 × age) − 161
That figure is then multiplied by an activity factor between 1.2 and 1.9 to give total daily energy expenditure. Your goal adjusts the target from there — a 20% reduction for weight loss, or a 15% increase for gain.
The macronutrient split starts from 1.6 g of protein per kilogram of bodyweight and 25% of energy from fat, with carbohydrate making up the remainder. Those are reasonable defaults, not prescriptions.
Turn the estimate into a plan
Knowing your number is the easy part. Building meals around it that you’ll actually keep eating is the part worth getting help with.