# Daily Calorie Needs Calculator

Calculate your daily calorie needs with our free calculator. Uses the Mifflin-St Jeor equation to determine BMR and total calories for weight loss.

## What this calculates

Knowing how many calories your body needs each day is essential for weight management. This calculator uses the Mifflin-St Jeor equation, considered the most accurate formula for estimating calorie needs, to help you determine your daily caloric requirements.

## Inputs

- **Gender** — options: Male, Female
- **Age** (years) — min 1, max 120
- **Weight** (kg) — min 20, max 300
- **Height** (cm) — min 100, max 250
- **Activity Level** — options: Sedentary (little or no exercise), Lightly active (1-3 days/week), Moderately active (3-5 days/week), Very active (6-7 days/week), Extra active (very hard exercise)

## Outputs

- **Basal Metabolic Rate** (Calories/day) — Calories burned at complete rest (Mifflin-St Jeor)
- **Maintenance Calories** (Calories/day) — Calories to maintain current weight
- **Mild Weight Loss** (Calories/day) — Deficit of ~250 Calories/day (~0.25 kg / ~0.5 lb per week)
- **Weight Loss** (Calories/day) — Deficit of ~500 Calories/day (~0.5 kg / ~1 lb per week)

## Details

The Mifflin-St Jeor equation was developed in 1990 and has been validated as the most reliable method for estimating resting metabolic rate in both normal-weight and obese individuals. It calculates your Basal Metabolic Rate (BMR) and then applies an activity multiplier to estimate your Total Daily Energy Expenditure (TDEE).

For weight loss, a moderate caloric deficit of 500 calories per day is generally recommended, which equates to approximately 0.5 kg (1 pound) of fat loss per week. Going below your BMR is not recommended as it can lead to muscle loss, nutritional deficiencies, and metabolic adaptation. Always consult a healthcare professional before starting any significant calorie restriction plan.

Factors such as body composition, hormonal status, medications, and medical conditions can affect your actual calorie needs. This calculator provides an estimate and should be used as a starting point for dietary planning.

## Frequently Asked Questions

**Q: What is the Mifflin-St Jeor equation?**

A: The Mifflin-St Jeor equation is a formula developed in 1990 that calculates your Basal Metabolic Rate (BMR). For men: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age - 5. For women: BMR = 10 x weight(kg) + 6.25 x height(cm) - 5 x age - 161. It is considered more accurate than the older Harris-Benedict equation by the American Dietetic Association.

**Q: How many calories should I eat to lose weight?**

A: A safe rate of weight loss is 0.5 to 1 kg per week, which requires a daily caloric deficit of 500 to 1,000 calories below your maintenance level. However, you should generally not eat below your BMR. Very low calorie diets should only be followed under medical supervision. Sustainable weight loss comes from moderate deficits combined with regular physical activity.

**Q: Why does activity level matter for calorie needs?**

A: Your BMR only accounts for the calories your body burns at complete rest. Physical activity can significantly increase your total daily energy expenditure. A sedentary person may only burn 20% more than their BMR, while a very active person may burn up to 90% more. Choosing the right activity level ensures your calorie estimate matches your actual lifestyle.

**Q: Are these calorie estimates exact?**

A: No, these are estimates based on population averages. Individual metabolic rates can vary by 10-15% due to factors like genetics, body composition, hormonal status, and environmental conditions. Use these numbers as a starting point and adjust based on your actual results over 2-4 weeks. Tracking your weight and food intake will help you fine-tune your calorie target.

---

Source: https://vastcalc.com/calculators/health/calorie
Category: Health & Fitness
Last updated: 2026-04-21