How Nahria calculates your targets
When you finish setting up, Nahria turns your profile into a daily calorie target and macronutrient targets (protein, fat and carbs). There is no black box: this page documents every formula the app uses — the same numbers you see in your plan.
Everything is computed from a handful of inputs: gender, age, height, weight, activity level, your goal and pace, and — if you set one — a goal weight.
Step 1 — Energy at rest (BMR)
Your basal metabolic rate (BMR) is the energy your body burns at complete rest. Nahria uses the Mifflin-St Jeor equation, which studies have repeatedly found to be the most accurate of the common BMR formulas for adults.
Male: 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Female: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Other: 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 78If you choose "other" as your gender, we use the average of the male and female constants. The equation is validated for adults (18+); for 16–17-year-olds it tends to estimate slightly low.
Step 2 — Total daily burn (TDEE)
Your total daily energy expenditure (TDEE) adds everyday movement and exercise on top of BMR, using a standard activity multiplier:
TDEE = BMR × activity multiplier| Activity level | Multiplier |
|---|---|
| Sedentary — little or no exercise | 1.2 |
| Lightly active — light exercise 1–3 days/week | 1.375 |
| Moderately active — moderate exercise 3–5 days/week | 1.55 |
| Very active — hard exercise 6–7 days/week | 1.725 |
| Extra active — very hard exercise plus a physical job | 1.9 |
Your TDEE is your maintenance level: eat roughly this many calories and your weight stays about the same.
Step 3 — Goal and pace
If your goal is to maintain your weight, your calorie target simply equals your TDEE. Otherwise Nahria applies a deficit or surplus as a percentage of your TDEE — not a fixed calorie amount — so the plan scales with your body instead of over- or undershooting for smaller or larger people.
Losing weight — the deficit for each pace:
| Pace | Deficit | ≈ kg per week* |
|---|---|---|
| Slow & steady | 10% | ~0.23 |
| Standard | 20% | ~0.45 |
| Accelerated | 25% | ~0.57 |
| Extreme | 30% | ~0.68 |
Gaining weight — the surplus for each pace:
| Pace | Surplus | ≈ kg per week* |
|---|---|---|
| Lean gain | 7% | ~0.16 |
| Standard | 10% | ~0.23 |
| Aggressive | 15% | ~0.34 |
| Extreme | 20% | ~0.45 |
Building muscle — smaller surpluses that favour lean gains over scale weight:
| Pace | Surplus | ≈ kg per week* |
|---|---|---|
| Conservative | 5% | ~0.11 |
| Lean | 7% | ~0.16 |
| Standard | 10% | ~0.23 |
| Aggressive | 15% | ~0.34 |
*Example rates at a TDEE of 2500 kcal (2500 × % × 7 ÷ 7700). The app shows previews based on your own TDEE. If you don't pick a pace, Standard is used.
Safety limits
Before a target becomes your plan, it has to pass a set of guardrails:
| Limit | Value |
|---|---|
| Minimum calories (female) | 1200 kcal/day |
| Minimum calories (male) | 1500 kcal/day |
| Minimum calories (other) | 1350 kcal/day |
| Maximum deficit | 1000 kcal/day |
| Maximum deficit share | 30% of TDEE |
These limits apply everywhere the numbers appear — including the weekly-change previews when you pick a pace — so what you see while choosing is exactly what your plan will do.
Weekly change and time to goal
Nahria converts your daily deficit or surplus into an expected weight change using the common approximation that one kilogram of body weight ≈ 7700 kcal:
weekly change (kg) = daily deficit or surplus × 7 ÷ 7700The time-to-goal estimate divides the distance to your goal weight by that rate, rounded up to whole weeks:
weeks to goal = ⌈ |current weight − goal weight| ÷ weekly change ⌉Step 4 — Macros: protein first, then fat, then carbs
Your calorie target is split into macronutrients in a deliberate order: protein and fat have minimum requirements, and carbohydrates fill whatever is left.
Protein depends on your goal:
| Goal | Protein |
|---|---|
| Maintain weight | 1.6 g/kg |
| Lose weight | 1.8 g/kg |
| Gain weight | 1.8 g/kg |
| Build muscle | 2.0 g/kg |
Protein never drops below 50 g/day and is capped at 2.5 g/kg. Fat gets 25% of your calories (30% when maintaining weight), with a floor of 0.8 g/kg for hormonal health. Carbohydrates take the remaining calories, with a floor of 50 g/day. (Energy per gram: protein 4 kcal, carbs 4 kcal, fat 9 kcal.)
One subtlety: the per-kilogram values use your scaling weight — the lower of your current and goal weight — rather than raw body weight. Protein needs track lean mass, not fat mass, so this stops the app from prescribing protein "for" weight you are trying to lose. When gaining, your current weight is used, so targets aren't inflated for muscle you haven't built yet.
A worked example
A 30-year-old man, 85 kg, 180 cm, moderately active, wants to reach 75 kg at the Standard pace:
- BMR = 10 × 85 + 6.25 × 180 − 5 × 30 + 5 = 1830 kcal
- TDEE = 1830 × 1.55 = 2837 kcal
- Deficit = 20% of 2837 = 567 kcal → daily target 2270 kcal
- Expected loss = 567 × 7 ÷ 7700 ≈ 0.52 kg/week → 10 kg in about 20 weeks
- Macros (scaled to the 75 kg goal weight): 135 g protein, 63 g fat, 291 g carbs
Good to know
These formulas are well-established population estimates — a starting point, not a lab measurement. Individual metabolisms can differ by a few hundred calories in either direction, and real-world weight change is noisier than the 7700 kcal rule suggests (water weight alone can mask weeks of progress). Track for a few weeks, compare the trend with the plan, and adjust your targets in the app if needed.
Nahria is not a medical device, and none of this is medical advice. If you are pregnant, under 18, have a history of disordered eating, or a condition that affects your metabolism, please talk to a doctor or dietitian before changing your diet.