Calculate Calories to Lose Weight

Weight Loss Calorie Calculator

Calculate your daily calorie needs for effective weight loss

Male Female

Sedentary (office job, little exercise) Lightly Active (1-3 days/week) Moderately Active (3-5 days/week) Very Active (6-7 days/week) Extra Active (Physical job or 2x training)

Your Daily Calorie Results

Maintenance (TDEE) 0 kcal/day

Weight Loss (0.5kg/week) 0 kcal/day

Extreme Loss (1kg/week) 0 kcal/day

function calculateCalories() { var gender = document.getElementById('gender').value; var weight = parseFloat(document.getElementById('weight').value); var height = parseFloat(document.getElementById('height').value); var age = parseInt(document.getElementById('age').value); var activity = parseFloat(document.getElementById('activity').value); var resultDiv = document.getElementById('results-container'); var warningText = document.getElementById('warning-text'); if (isNaN(weight) || isNaN(height) || isNaN(age) || weight <= 0 || height <= 0 || age <= 0) { alert('Please enter valid positive numbers for all fields.'); return; } // Mifflin-St Jeor Equation var bmr; if (gender === 'male') { bmr = (10 * weight) + (6.25 * height) – (5 * age) + 5; } else { bmr = (10 * weight) + (6.25 * height) – (5 * age) – 161; } var tdee = bmr * activity; var loss = tdee – 500; var extremeLoss = tdee – 1000; // Health safety floors var minCals = (gender === 'female') ? 1200 : 1500; var showWarning = false; if (loss < minCals) { loss = minCals; showWarning = true; } if (extremeLoss < minCals) { extremeLoss = minCals; showWarning = true; } document.getElementById('maintenance-result').innerText = Math.round(tdee).toLocaleString(); document.getElementById('loss-result').innerText = Math.round(loss).toLocaleString(); document.getElementById('extreme-result').innerText = Math.round(extremeLoss).toLocaleString(); if (showWarning) { warningText.innerText = "Note: Calorie suggestions have been adjusted to meet the minimum recommended safety floor (" + minCals + " kcal) for your gender."; } else { warningText.innerText = ""; } resultDiv.style.display = 'block'; resultDiv.scrollIntoView({ behavior: 'smooth' }); }

How to Calculate Calories to Lose Weight Safely

Weight loss is fundamentally driven by a calorie deficit—consuming fewer calories than your body burns. To find your ideal target, you first need to determine your Total Daily Energy Expenditure (TDEE), which is the sum of your resting metabolic rate and the calories burned through movement.

The Science of the Deficit

One pound of body fat is approximately equal to 3,500 calories. By creating a daily deficit of 500 calories, you can theoretically lose about 0.5kg (1lb) per week. Our calculator uses the Mifflin-St Jeor Formula, widely regarded by nutrition professionals as the most accurate way to estimate metabolic needs.

Example Calculation

Consider a 35-year-old male weighing 90kg at 180cm tall with a moderate activity level:

• BMR (Basal Metabolic Rate): ~1,870 calories (what he burns at rest).
• TDEE (Maintenance): ~2,900 calories (with activity).
• Weight Loss Goal: To lose 0.5kg/week, he should aim for 2,400 calories daily.

Important Safety Considerations

While cutting calories is necessary for weight loss, going too low can be counterproductive. Extremely low-calorie diets can lead to muscle loss, nutrient deficiencies, and a slowed metabolism. Medical professionals generally recommend that women should not consume fewer than 1,200 calories and men no fewer than 1,500 calories per day unless supervised by a physician.

Pro Tip: Focus on protein intake and resistance training while in a calorie deficit. This ensures that the weight you lose comes from body fat rather than lean muscle tissue.