ƒEquations covered

BMR Mifflin–St Jeor — often the most accurate for the general population.
BMR Harris–Benedict (revised) — an older but still used formula.
LBM Katch–McArdle — based on lean mass, more relevant if you know your body fat %.
LBM Cunningham — close to Katch, used in sports/physiology for RMR.

ℹ︎How to interpret the result

BMR is resting expenditure. TDEE = BMR × activity factor (1.2 to 1.9).
For ~0.5 kg/week weight loss, a ~500 kcal/day deficit is a practical rule of thumb.
Avoid dropping below ~1200 kcal (women) / ~1500 kcal (men) without medical advice.

Warning

Avoid going below ~1200 kcal (women) / ~1500 kcal (men) without medical advice.

–Calorie counting for weight loss

Determine your BMR, then apply a reasonable deficit.
Track intake with an app or journal and adjust based on progress.
Measure over at least a week to smooth water fluctuations.

ZCalorie zigzag (cycling)

Alternate higher and lower calorie days while keeping the same weekly total.
Example: 2300 kcal × 3 days and 1775 kcal × 4 days ↔ 2000 kcal × 7 days ≈ 14000 kcal.
Helps avoid plateaus and adds social flexibility.

Tip: plan higher-calorie days around social events to keep flexibility while respecting the weekly total.

✓How many calories do you need?

Depends on age, sex, height, weight, activity and overall health.
Generally: ~2000–3000 kcal/day for men, ~1600–2400 for women (US DHHS).
Too few calories may impair energy, recovery and lean mass.

≡Calories: types and effects

Prioritize minimally processed foods high in protein and fiber for satiety.
Drinks can represent ~20% of intake: limit added sugars.
Macronutrients: protein/carbs ≈ 4 kcal/g, fats ≈ 9 kcal/g.

Formulas and variables

Equation	Sex	Formula
Mifflin–St Jeor	Male	BMR = 10W + 6.25H − 5A + 5
Mifflin–St Jeor	Female	BMR = 10W + 6.25H − 5A − 161
Harris–Benedict (revised)	Male	BMR = 13.397W + 4.799H − 5.677A + 88.362
Harris–Benedict (revised)	Female	BMR = 9.247W + 3.098H − 4.330A + 447.593
Katch–McArdle	Both	BMR = 370 + 21.6 × LBM (LBM = W × (1 − F))
Cunningham	Both	RMR = 500 + 22 × LBM

W: Weight (kg)
H: Height (cm)
A: Age (years)
F: Body fat (%)
LBM: Lean body mass (kg)

Worked example

Data: Male, 30 y, 70 kg, 175 cm, moderate activity (1.55).
BMR (Mifflin): 10×70 + 6.25×175 − 5×30 + 5 ≈ 1668 kcal/day.
TDEE: 1668 × 1.55 ≈ 2585 kcal/day.
Loss target: ~2585 − 500 ≈ 2085 kcal/day.
Macros (30/45/25): Prot ≈ 2085×0.30/4 ≈ 156 g; Carbs ≈ 234 g; Fat ≈ 58 g.

Example daily meal plans

Meal	1200 kcal	1500 kcal	2000 kcal
Breakfast	All‑Bran cereal (125), Milk (50), Banana (90)	Granola (120), Greek yogurt (120), Blueberries (40)	Buttered toast (150), Egg (80), Banana (90), Almonds (170)
Lunch	Tomato grilled cheese (300), Salad (50)	Chicken/veg soup (300), Bread (100)	Grilled chicken (225), Grilled veggies (125), Pasta (185)
Snack	Cucumber (30), Avocado dip (50)	Orange (70), Greek yogurt (120)	Hummus (50), Carrot sticks (35), Crackers (65)
Dinner	Grilled chicken (200), Brussels sprouts (100), Quinoa (105)	Steak (375), Mashed potatoes (150), Asparagus (75)	Salmon (225), Brown rice (175), Green beans (100), Nuts (165)

Calories burned (1h) by weight

Activity	57 kg	70 kg	84 kg
Golf (with cart)	198	246	294
Walking (5.6 km/h)	215	267	319
Kayaking	283	352	420
Swimming (moderate crawl)	397	492	587
Tennis (general)	397	492	587
Running (6:00 min/km)	624	773	923

kcal / h

Energy per gram (common components)

Component	kJ/g	kcal/g
Fat	37	9
Protein	17	4
Carbohydrates	17	4
Fiber	8	2
Alcohol (ethanol)	29	7
Polyols (sugar alcohol)	10	2.4

Note

Indicative examples (kcal per serving): apple 59, banana 151, chicken (100 g) 165, cooked rice (1 cup) 206, pizza (1 slice 14") 285, 1% milk (1 cup) 102, yogurt (1 cup) 110–154.

Disclaimer: educational information only; not medical advice. Consult a healthcare professional for a tailored plan.

Calorie Calculator

Macronutrient split (g/day)

Needed vs consumed

Energy converter (kcal ⇄ kJ)

BMR/TDEE calculation and complete guide to calories