Calorie Calculator
Find your daily calorie target, see your weight goal timeline and macro split
Results & Details
// Goal Weight Timeline
// Recommended Macro Split
// Your Daily Budget In Food
How This Calculator Works
This calculator uses the Mifflin-St Jeor equation to calculate your BMR, multiplies by your activity level to get TDEE, then adjusts by your chosen calorie goal to produce a daily target. The weight timeline shows how long it will take to reach your goal weight at that deficit or surplus.
The Calorie Deficit Rule
A deficit of approximately 7,700 calories produces 1 kg of fat loss (3,500 calories ≈ 1 lb). A daily deficit of 500 calories therefore produces around 0.5 kg of fat loss per week. This is a widely-used estimate — actual results vary based on individual metabolism, water retention, and other factors.
Macro Split Guidelines
How Much Should I Eat?
A safe rate of weight loss is 0.5–1 kg per week. Larger deficits risk muscle loss and metabolic adaptation. If your calculated target falls below 1,200 calories (women) or 1,500 calories (men), you should consult a healthcare professional before proceeding.
Calories: The Numbers Behind the Estimate
Built and verified by Andrius R. · Updated June 2026
Every calorie calculator runs on the same logic: estimate your resting burn, scale it for activity, then adjust for your goal. Here is each step with real numbers, plus the error bars nobody mentions.
Step 1 — BMR: what you burn doing nothing
This calculator uses the Mifflin-St Jeor equation, which research has found to be the most accurate of the common formulas for most adults:
Men: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5
Women: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age − 161
Example: a 30-year-old man, 80 kg, 180 cm → 800 + 1,125 − 150 + 5 = 1,780 kcal/day.
A 30-year-old woman, 65 kg, 165 cm → 650 + 1,031 − 150 − 161 = ~1,370 kcal/day.
Step 2 — TDEE: scaling for real life
| Activity level | Multiplier | Example (BMR 1,780) |
|---|---|---|
| Sedentary (desk job, little exercise) | ×1.2 | ~2,136 kcal |
| Light (1–3 sessions/week) | ×1.375 | ~2,448 kcal |
| Moderate (3–5 sessions/week) | ×1.55 | ~2,759 kcal |
| Very active (6–7 sessions/week) | ×1.725 | ~3,071 kcal |
Most people overestimate their activity level by one tier. If results stall, recalculate one level down.
Step 3 — Adjusting for a goal
A long-standing approximation: one pound of body fat stores roughly 3,500 kcal (about 7,700 kcal per kg). A 500 kcal/day deficit therefore targets ~1 lb (~0.45 kg) per week. It's a useful planning number, though real-world loss slows over time as your body adapts and gets lighter — the "3,500 rule" overestimates long-term results, so treat week-by-week scale data as the real feedback loop.
- Sustainable fat loss: deficit of 300–500 kcal/day. Larger deficits work short-term but cost muscle and adherence.
- Muscle gain: surplus of 200–300 kcal/day with resistance training; more mostly adds fat.
- Floor: prolonged intakes below ~1,200 kcal (women) / ~1,500 kcal (men) generally need medical supervision.
Honest error bars
Every number above is an estimate stacked on an estimate. Mifflin-St Jeor is typically within ±10% of measured metabolism — that's ±180 kcal on our example before the activity multiplier adds its own uncertainty. Meanwhile, food-label calories are legally allowed meaningful tolerance, and portion estimation errors of 20%+ are routine. The practical method: take the calculator's number as a starting point, hold it for two to three weeks, watch the weekly average on the scale, and adjust by 100–200 kcal at a time. Your own data beats any formula.
Where the calories go (and the metabolism myth)
For a typical person, BMR is 60–70% of daily burn, day-to-day movement (NEAT — fidgeting, walking, posture) is 10–20%, digestion ~10%, and deliberate exercise often a surprisingly small 5–10%. Two consequences: "slow metabolism" differences between similar people are usually modest, and daily movement frequently moves the needle more than the gym session does. Exercise remains essential — for health, muscle retention and appetite regulation — but the eating side controls the energy balance.
From the Blog
// 500 kcal Rule
A 500 kcal daily deficit produces about 0.5 kg of fat loss per week — a safe and sustainable rate for most people.
// Protein First
High protein intake (1.6–2.2 g/kg bodyweight) preserves muscle mass during a calorie deficit, especially with resistance training.
// Don't Go Too Low
Eating below BMR for extended periods slows metabolism and causes muscle loss. The minimum safe intake is ~1,200 kcal for women and ~1,500 kcal for men.
// Diet Breaks
Taking 1–2 week diet breaks at maintenance every 6–8 weeks can reduce metabolic adaptation and improve long-term adherence.