Calorie Deficit Calculator
Calculate how many calories you need to eat daily to reach your target weight by your goal date. Uses the Mifflin-St Jeor equation for accurate BMR estimation.
Expect more details here after you have entered all the necessary information above.
Understanding Calorie Deficit
What is a Calorie Deficit?
A calorie deficit occurs when you consume fewer calories than your body burns. This forces your body to use stored energy (fat) for fuel, resulting in weight loss. The formula is simple:
How Much Deficit Do You Need?
To lose weight at different rates, you need these approximate deficits:
- 0.5 lb per week: 250 calorie daily deficit
- 1 lb per week: 500 calorie daily deficit (recommended)
- 1.5 lbs per week: 750 calorie daily deficit
- 2 lbs per week: 1,000 calorie daily deficit (maximum safe)
Safe Minimum Calories
Health experts recommend not going below these daily calorie minimums:
Women
1,200 calories
minimum per day
Men
1,500 calories
minimum per day
Tips for Success
- Start with a moderate deficit (500 calories) for sustainable results
- Track your food intake accurately using a food diary or app
- Include protein in every meal to preserve muscle mass
- Combine diet with exercise for better results and health
- Be patient - healthy weight loss takes time
- Adjust your calories as your weight changes
Frequently Asked Questions
How accurate is this calorie deficit calculator?
This calculator uses the Mifflin-St Jeor equation, which is considered one of the most accurate formulas for estimating BMR. However, individual results may vary based on metabolism, muscle mass, and other factors. Use the results as a starting point and adjust based on your actual progress.
Is a 1000 calorie deficit safe?
A 1000 calorie deficit can lead to rapid weight loss (about 2 lbs/week) but may be difficult to sustain and could lead to muscle loss, nutrient deficiencies, and metabolic slowdown. Most experts recommend a 500 calorie deficit for sustainable, healthy weight loss.
Why am I not losing weight despite being in a deficit?
Several factors can affect weight loss: inaccurate calorie counting, water retention, metabolic adaptation, underestimating food portions, or overestimating exercise calories burned. Try tracking more precisely or consult a healthcare professional.
Should I eat back exercise calories?
It depends on your goals. If your deficit is moderate (500 cal), you might eat back some exercise calories to fuel workouts. If your deficit is already aggressive, eating back all exercise calories may slow progress. A good middle ground is eating back 50% of exercise calories.
How often should I recalculate my calorie needs?
Recalculate every 10-15 pounds lost, or monthly. As you lose weight, your TDEE decreases, so your calorie target needs to be adjusted to continue losing weight at the same rate.
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest. TDEE (Total Daily Energy Expenditure) includes BMR plus calories burned through daily activities and exercise. TDEE = BMR × Activity Factor.
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