How to Use Weight Loss Calculator
The Weight Loss Calculator estimates your recommended daily calorie intake and timeline to reach your goal weight. Fill in your details and the Weight Loss Calculator generates your personalised plan instantly.
- Gender — Select male or female. This affects the BMR formula constants.
- Age, Height, Current Weight — Enter accurate values for the most reliable BMR estimate.
- Target Weight — Must be less than your current weight for the Weight Loss Calculator to compute a deficit.
- Activity Level — Choose the option that best describes your typical weekly exercise habits. Honest self-assessment leads to better results.
- Weekly Weight Loss Goal — Set your desired rate (e.g. 0.5 kg/week is a moderate, sustainable target).
The Weight Loss Calculator then shows your BMR, TDEE, recommended daily calorie intake, estimated days to goal, and projected completion date.
Formula & Theory — Weight Loss Calculator
The Weight Loss Calculator follows a two-step process:
Step 1 — Calculate BMR using Mifflin-St Jeor:
Male: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Female: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Step 2 — Multiply by activity factor to get TDEE:
| Activity Level | Factor |
|---|---|
| Sedentary | × 1.20 |
| Lightly Active | × 1.375 |
| Moderately Active | × 1.55 |
| Very Active | × 1.725 |
| Extra Active | × 1.90 |
Step 3 — Calculate daily calorie target:
Daily Deficit = Weekly Goal (kg) × 7,700 ÷ 7
Daily Intake = TDEE − Daily Deficit
The Weight Loss Calculator also enforces a safety floor: 1,500 kcal/day for men and 1,200 kcal/day for women. If your target intake falls below this, a warning is displayed.
Important Disclaimer
The results from this Weight Loss Calculator are estimates only. Individual metabolic rates vary. Results should not substitute professional medical or nutritional advice.
Use Cases for Weight Loss Calculator
The Weight Loss Calculator is a practical tool across a range of health and fitness goals:
- Pre-diet planning — Use the Weight Loss Calculator to understand your maintenance calories before starting a new eating plan.
- Goal-setting for events — Determine whether your goal weight is achievable before a wedding, holiday, or sporting event.
- Fitness coaching — Personal trainers can use the Weight Loss Calculator as a starting point to build client meal plans.
- Tracking plateaus — As you lose weight, your BMR decreases; re-run the Weight Loss Calculator periodically to adjust your intake target.
- Understanding activity impact — Compare TDEE across different activity levels to see how exercise affects your daily energy budget.
The Weight Loss Calculator is most effective when combined with consistent physical activity, adequate sleep, and balanced nutrition. Always consult a registered dietitian or physician for personalised medical advice.