Professional
Calorie Calculator
Estimate your BMR, TDEE and smart calorie targets for fat loss, maintenance or muscle gain – using evidence-based equations and practical coaching rules.
Calculator settings
This tool is intended for generally healthy adults. For medical conditions, pregnancy or elite sport preparation, work directly with a qualified professional.
Results
Enter your information and click “Calculate” to see your personalised calorie targets.
Based on a 40% carbs, 30% protein, 30% fats split – a solid default for most training clients.
Quickly convert between Calories (kcal) and kilojoules (kJ).
How this calorie calculator works
This tool first estimates your Basal Metabolic Rate (BMR) – the calories your body burns at rest – using the modern Mifflin-St Jeor equation. It then multiplies that by an activity factor to estimate your Total Daily Energy Expenditure (TDEE), which is the number of calories you need on an average day to maintain your current weight.
From your TDEE we generate structured targets for fat loss, maintenance and muscle gain. Instead of random numbers, each target is a clear percentage above or below maintenance so you can make precise, scientific adjustments.
Formulas used
By default the calculator uses the Mifflin-St Jeor equation for BMR, which performs very well in modern research for healthy adults.
Mifflin-St Jeor (BMR):
Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Your TDEE is then:
- Sedentary: BMR × 1.2
- Light: BMR × 1.375
- Moderate: BMR × 1.55
- Active: BMR × 1.725
- Athlete: BMR × 1.9
How we set calorie targets
Your targets are not random – they follow clear, coach-tested ranges:
- Maintain: ~100% of TDEE.
- Mild loss: ~90% of TDEE – easier to sustain.
- Fat loss: ~80% of TDEE – typical -0.5 kg / week.
- Aggressive cut: ~65–70% of TDEE – short-term only.
- Mild gain: ~110% of TDEE – lean muscle gain.
- Faster gain: ~120% of TDEE – expect some fat gain.
Real-world progress, body composition and health markers should always guide final adjustments.
What about “zigzag” or calorie cycling?
Many people like to keep some days a little higher in calories (for hard training sessions or social events) and compensate with slightly lower-calorie days. This is often called zigzag calorie cycling. As long as the weekly average matches your target, fat loss and muscle gain can still be excellent.
A simple strategy is to keep two higher-calorie days close to maintenance and five days at your fat-loss target. The total weekly calories stay the same, but your lifestyle feels more flexible.
This calculator is a coaching and education tool and does not replace medical advice. Consult your doctor or a registered dietitian if you have medical conditions, take medication that affects weight or appetite, or plan to lose weight rapidly.