Calculate the optimal calorie deficit for your clients to lose fat safely and sustainably. Includes visual timeline, safety warnings and recommended minimum calories.
If known, the calculation will be more accurate using the Katch-McArdle formula.
Moderate exercise 3-5 days/week
Manage your clients, build custom programs and track their progress. Everything in one professional platform.
Your cutting calories are calculated by subtracting a deficit from your Total Daily Energy Expenditure (TDEE). A conservative cut subtracts 300 kcal/day, a moderate cut 500 kcal/day and an aggressive cut 750 kcal/day. Most coaches recommend starting with a moderate deficit of 300-500 kcal, which typically produces 0.3-0.6 kg of fat loss per week while preserving lean mass.
The calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR), then multiplies it by your activity factor to get TDEE. If you provide your body fat percentage, it switches to the more accurate Katch-McArdle formula, which calculates BMR from lean body mass rather than total weight.
A well-structured cutting phase typically lasts 8-16 weeks. Longer deficits increase the risk of negative metabolic adaptations, hormonal suppression and muscle loss. The leaner you already are, the smaller the deficit should be — someone at 25% body fat can tolerate a larger deficit than someone at 12%.
Never go below 1500 kcal for men or 1200 kcal for women. These floors exist to ensure adequate micronutrient intake, maintain hormonal function and prevent excessive lean mass loss. If your TDEE minus your target deficit falls below these values, increase activity instead of cutting calories further.