Calorie Deficit Calculator for Sustainable Weight Loss

Set personalized deficit targets backed by science and safety guidelines

Quick answer

A daily deficit of 500–750 calories below maintenance typically produces 1–1.5 pounds of weekly weight loss for most adults. Larger bodies can temporarily sustain bigger deficits, but dropping below 1,200 kcal/day for women or 1,500 kcal/day for men should be supervised by a professional. Get your maintenance number in the calorie calculator, then subtract your target deficit.

Understanding TDEE and maintenance calories

Total Daily Energy Expenditure (TDEE) combines four parts:

1. BMR — basal metabolic rate, the energy to simply stay alive (usually 60–70% of TDEE)
2. NEAT — non-exercise activity: walking, standing, fidgeting (highly variable, 10–30%)
3. Exercise — deliberate workouts (typically 5–10%)
4. TEF — the thermic effect of digesting food (~10%)

Our calculator estimates TDEE using the Mifflin-St Jeor equation and activity multipliers. For a 35-year-old woman at 75 kg and 165 cm with light activity: BMR ≈ 1,465 kcal, TDEE ≈ 2,010 kcal. Subtracting a 500-calorie deficit gives a 1,510 kcal daily target — about 1 pound per week.

Deficit sizing table

Choosing the right deficit for your timeline

A 10–15% deficit suits long-term, sustainable loss. Athletes preparing for events may run 20–25% deficits for short phases. Plan diet breaks every 8–12 weeks to restore training quality and preserve lean mass, especially when dieting aggressively. Monitor energy, sleep, and mood — if they tank, scale the deficit back before your adherence does.

Macros, activity, and plateaus

Distribute calories across:

• Protein: 0.8–1.0 g per pound of goal body weight — the lever that protects muscle
• Fats: 20–30% of calories for hormones and satiety
• Carbohydrates: the remainder, fueling training and daily activity

When progress stalls — and it will — the cause is usually adaptive: TDEE falls as you lose weight and NEAT drops without you noticing. Before cutting calories further, verify logging accuracy (measuring, not eyeballing), take a diet break at maintenance for 1–2 weeks, and increase daily steps. Re-run your numbers in the calorie calculator at your new weight; a deficit that worked at 90 kg can be maintenance at 80 kg.

Deficit survival strategies

• Pre-log meals to avoid last-minute calorie surprises.
• Build meals around high-volume, low-calorie foods — vegetables, broth soups, lean proteins.
• Keep protein at every meal; it is the most satiating macro.
• Weigh yourself daily but judge only the 7-day average.
• Watch for warning signs — dizziness, hair loss, extreme fatigue — and consult a health professional if they appear.

Putting the numbers in context

A calorie deficit is the mechanism of weight loss, but the quality of the plan decides whether you keep the result. Pair your target with strength training to preserve muscle, and check where you stand with the BMI calculator or set a long-term target range with the ideal weight calculator.

Commit to gradual, data-driven fat loss

Calorie deficits work when they are sustainable. Choose a target that respects your lifestyle, monitor biofeedback weekly, and adjust intake or activity instead of chasing drastic cuts.