Your results will appear here.
Enter your values and press Calculate.
Enter gender, age, weight, height, activity level, and the daily deficit you want. The calculator finds BMR with the Mifflin-St Jeor equation, multiplies by your activity factor for TDEE, subtracts the deficit for your daily target, and converts the deficit into weekly and monthly loss using 7,700 kcal per kg (3,500 kcal per lb).
A calorie deficit means eating fewer calories than your body uses in a day. The shortfall is covered from stored energy, mostly body fat, so weight falls over time. The deficit itself is the gap between your TDEE (everything you burn) and what you eat.
Enter your details and pick an activity level honestly: most desk workers are sedentary or lightly active, not moderately active. Choose a deficit, and the results panel shows BMR, TDEE, your daily calorie intake target, weekly loss in kg and lb, monthly loss, and a safety check on the target.
For men: BMR = 10 × weight in kg + 6.25 × height in cm - 5 × age + 5. For women: the same, but minus 161 instead of plus 5. TDEE is BMR times an activity multiplier: 1.2 sedentary, 1.375 lightly active, 1.55 moderately active, 1.725 very active, 1.9 extra active. Your daily target is TDEE minus your deficit.
BMR = 700 + 1,031.25 - 150 - 161 = 1,420.25 kcal. TDEE = 1,420.25 × 1.55 = 2,201.39 kcal. Target = 2,201.39 - 500 = 1,701.39 kcal per day. Weekly loss = 500 × 7 / 7,700 = 0.45 kg (1 lb). Monthly loss is about 1.95 kg.
Use this chart of deficit sizes to pick a pace you can sustain. A good calorie deficit for most adults is 500 kcal a day, losing about 1 pound per week. A 250 kcal daily deficit loses about 0.5 lb (0.23 kg) per week. 500 kcal loses about 1 lb (0.45 kg). 750 kcal loses about 1.5 lb (0.68 kg). 1,000 kcal loses about 2 lb (0.91 kg). Above 1,500 kcal a day, loss passes 3 lb per week and is not recommended for most people.
The commonly cited safe range for most adults is a 500 to 600 kcal daily deficit, losing 0.5 to 1 kg per week. Minimum intakes often cited are 1,200 kcal per day for women and 1,500 for men, unless medically supervised. This calculator flags any target below those floors, below BMR, or from a deficit above about 35% of TDEE.
As you lose weight, BMR and TDEE fall because a smaller body burns less, and the body adapts (metabolic adaptation). Water and glycogen shifts also mask fat loss early on. That is why calculators say recalculate every 4 to 6 weeks or every 5 kg lost. A weight loss plateau is normal during a long deficit, not a sign of failure.
In a deficit, protein protects muscle: a daily protein intake of 1.6 to 2.2 g per kg of body weight per day, with resistance training, is the range competitors cite. Without enough protein and training, a larger share of the loss comes from muscle instead of fat.
Underestimating portions by 20% to 50%, hidden oils and sauces, liquid calories, weekend overeating erasing the weekly deficit, and eating back exercise calories (double counting, since TDEE already includes activity). Track honestly for a few weeks before judging the target.
A 1 to 2 week break at maintenance every 8 to 12 weeks can help adherence and recovery. Recalculate your target whenever weight, activity, or both change materially, roughly every 4 to 6 weeks.
These results are estimates from population-average equations, not professional medical advice. They do not replace advice from a doctor or registered dietitian, especially if you have a medical condition, are pregnant, or are under 18. Never chase very large or prolonged deficits without supervision.
Eating fewer calories than your total daily energy expenditure (TDEE), so the body covers the gap from stored energy and weight falls.
Find BMR with Mifflin-St Jeor, multiply by an activity factor for TDEE, then subtract your chosen deficit. This calculator does all three steps.
Your TDEE minus a moderate deficit, usually 500 kcal. For the worked example above that is about 1,701 kcal per day.
About 500 kcal per day, since a pound of body fat is roughly 3,500 kcal and 500 × 7 = 3,500.
About 1,100 kcal per day, since a kilogram of body fat is roughly 7,700 kcal and 1,100 × 7 = 7,700. That pace is aggressive for most people.
For most healthy adults, yes: it is the standard moderate deficit, losing about 1 lb (0.45 kg) per week.
It can be for larger adults under supervision, but it is the upper end for most people and pushes targets near or below BMR. The safety check on this page will flag it.
BMR vs TDEE is the key distinction. BMR is what you burn at complete rest. TDEE is BMR times an activity multiplier, covering movement, exercise, and daily life. Your calorie target comes from TDEE, not BMR.
Usually no. TDEE already includes your activity level, so adding exercise calories back double counts them and erases the deficit.
Common causes: portions underestimated, weekend overeating, activity overestimated, water retention masking fat loss, or the target never recalculated after weight loss.
A smaller body burns fewer calories, and metabolic adaptation lowers expenditure further. Recalculate every 4 to 6 weeks and expect slower loss over time.
Most guidance points to 0.5 to 1 kg (1 to 2 lb) per week for most adults, slower for leaner people.
Reasonably close for planning, typically within 10% to 20% of true expenditure. Different calculators give different numbers because they use different equations and activity factors.
Total calories drive fat loss, but protein (1.6 to 2.2 g per kg per day) protects muscle, and fiber and protein improve fullness.
No. Fat loss requires an energy shortfall; exercise, fasting, and diets all work by creating one, whether or not you count it.
Divide the weight to lose by your weekly loss rate. Losing 10 kg at 0.45 kg per week takes about 22 weeks; at 0.91 kg per week it takes about 11 weeks, but that pace is harder to sustain. Losing 10 pounds at 1 pound per week takes about 10 weeks.
Calculate your Basal Metabolic Rate and daily calorie needs.
Tape-measure body fat estimate with the US Navy method, plus your fitness category.
Split your daily calories into protein, carb and fat grams with goal-based presets for cutting, maintaining or bulking.