Calorie Deficit Calculator
Find out how many calories to eat per day to lose fat at a safe, sustainable rate.
Daily Calorie Target
— cal/day
Estimated Weekly Fat Loss
— kg/week
Based on ~7,700 calories per kg of body fat. Actual results vary based on metabolism, activity, and adherence.
About this calculator
A calorie deficit occurs when you consume fewer calories than your body burns, forcing it to use stored energy (primarily body fat) to make up the difference. While the concept is simple, choosing the right size deficit is crucial. Research shows that moderate deficits of 300-500 calories per day produce the best long-term results. They are aggressive enough for visible progress, but sustainable enough to maintain muscle, energy, and adherence. Deficits larger than 25% of your TDEE significantly increase the risk of muscle loss, hormonal disruption, and metabolic adaptation. This calculator helps you find the sweet spot based on your TDEE, so you lose fat at a sustainable rate of roughly 0.5-1% of body weight per week.
Frequently asked questions
What is a safe weekly rate of fat loss?
Aim to lose 0.5-1% of your body weight per week. For a 180 lb person, that is about 0.9-1.8 lbs per week. Faster rates increase muscle loss, drive up hunger, and are harder to sustain. If you have more fat to lose, you can safely lose at the higher end of this range.
Will a calorie deficit cause muscle loss?
Some muscle loss is normal during a deficit, but you can minimize it by keeping protein high (1.6-2.2 g/kg), resistance training consistently, and keeping the deficit moderate. Studies show that people who do all three retain the vast majority of their muscle mass.
Why has my fat loss stalled?
Fat loss plateaus typically happen because your TDEE has decreased as you have lost weight. Recalculate your TDEE at your current weight and adjust your calorie target. Also account for increased water retention, diet fatigue leading to unconscious calorie creep, and reduced NEAT.
These numbers are a starting point. If you want help turning them into a plan you'll actually stick to, I do 1-on-1 coaching.
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