Sustainable fat loss comes down to one fundamental principle: consuming fewer calories than your body burns. But “eat less” is not a plan — it’s a direction. To lose weight at a specific pace without losing muscle or crashing your metabolism, you need to know your exact numbers.

This calculator uses the Mifflin-St Jeor equation — the gold standard for estimating calorie needs — to calculate your Total Daily Energy Expenditure (TDEE) and then determines the precise daily calorie target needed to reach your goal weight at your chosen pace.

## How This Calculator Works

The calculator first estimates your Basal Metabolic Rate (BMR) — the calories your body burns at rest — using the Mifflin-St Jeor formula, which accounts for weight, height, age, and sex. This is then multiplied by your activity factor to produce your TDEE. Your chosen weekly loss pace determines the daily calorie deficit, which is subtracted from your TDEE to give your target intake.

**One pound of fat ≈ 3,500 calories. One kilogram ≈ 7,700 calories.** A daily deficit of 500 calories produces approximately 0.5kg (1 lb) of loss per week.

## Choosing the Right Pace

**Slow (0.25 kg/week):** Ideal for people close to their goal weight, athletes trying to minimize muscle loss, or anyone who has struggled with aggressive diets in the past. The smallest deficit produces the most sustainable results.

**Moderate (0.5 kg/week) — Recommended:** The sweet spot supported by most nutrition research. Large enough to produce meaningful progress, small enough to preserve muscle mass and keep energy levels stable.

**Aggressive (0.75 kg/week):** Appropriate for people with significant weight to lose who are working with a structured plan. Requires strict adherence and higher protein intake to protect muscle.

**Fast (1 kg/week):** The maximum recommended rate for most people. Only suitable for those who are significantly overweight or doing so under medical supervision. Intakes below 1,500 kcal (men) or 1,200 kcal (women) are not recommended without professional guidance.

## What to Do With Your Calorie Target

Your calorie target is a daily average — not a rigid daily rule. Hitting your target consistently across the week matters more than hitting it exactly every day.

Focus on:

– **Protein first** — hit your protein target before filling the remaining calories with fats and carbs

– **Whole foods** — more volume, more fiber, more satiety per calorie

– **Tracking** — even rough tracking (using an app like MyFitnessPal for 2–4 weeks) dramatically improves accuracy

– **Patience** — weight fluctuates daily due to water, sodium, and hormones. Judge progress over 2–4 week averages

## Frequently Asked Questions

**What is a calorie deficit?**

A calorie deficit occurs when you consume fewer calories than your body expends in a given period. Over time, your body compensates by burning stored fat for energy, resulting in weight loss.

**How accurate is the Mifflin-St Jeor formula?**

It is the most validated formula for estimating calorie needs in healthy adults. Studies show it predicts resting metabolic rate within 10% for most people. Individual variation exists — if you’re not losing weight at your calculated deficit after 2–3 weeks, reduce intake by 100–150 kcal and reassess.

**Why am I not losing weight in a calorie deficit?**

The most common reasons are underestimating food intake (portions are larger than estimated), overestimating activity level, water retention masking fat loss, or metabolic adaptation after extended dieting. Recalculate your TDEE and consider a 1–2 week diet break before resuming.

**Is it safe to be in a calorie deficit every day?**

Yes, for most healthy adults. The key is choosing a moderate deficit and maintaining adequate protein intake. Extreme deficits (more than 1,000 kcal/day below TDEE) increase the risk of muscle loss, nutrient deficiency, and metabolic slowdown.

**Should I eat back exercise calories?**

This depends on how you estimated your activity level. If you chose “moderately active” based on your exercise, those calories are already factored into your TDEE — don’t add them back. If you chose “sedentary” and then exercised, you can eat back 50–75% of calories burned.

**What is TDEE?**

TDEE stands for Total Daily Energy Expenditure — the total number of calories your body burns in a day, including your resting metabolic rate plus all physical activity. It is your maintenance calorie level: eating exactly at TDEE produces no weight change.

## Related Tools & Articles

→ [Protein Intake Calculator](/your-daily-protein-target-calculator/) — Set your protein target alongside your calorie goal

→ [Fat Burn Zone Calculator](/fat-burn-zone-calculator/) — Optimize your cardio to complement your calorie deficit

→ [Metabolic Age Calculator](/whats-yourmetabolic-age/) — See how your metabolism compares to your peers

→ [CitrusBurn Review](/citrusburn-review/) — How thermogenic supplements support a calorie deficit