Free Calorie Deficit Calculator

How This Calculator Works

Our calorie deficit calculator uses the Mifflin-St Jeor equation to calculate your Total Daily Energy Expenditure (TDEE), then determines the optimal calorie deficit based on your desired weight loss rate:

TDEE Calculation: We calculate your Basal Metabolic Rate (BMR) and multiply it by your activity level to get your maintenance calories
Calorie Deficit: Based on the principle that 1 pound of fat = 3,500 calories, we calculate your daily deficit needed
Timeline Estimation: We project when you'll reach your goal weight based on consistent adherence to your calorie target

For a deeper understanding of calorie deficits, check out our comprehensive Calorie Deficit Guide.

Understanding Your Results

TDEE (Maintenance Calories): The number of calories you burn each day including all activities. Eating at this level maintains your current weight.
Daily Target Calories: The recommended calorie intake to achieve your desired weight loss rate while maintaining energy and health.
Daily Deficit: The number of calories below your TDEE you need to maintain each day to reach your goal.
Weekly Deficit: Your total weekly calorie reduction, which translates directly to fat loss over time.
Timeline: An estimate of when you'll reach your goal weight based on consistent adherence to your calorie target.

Safe Weight Loss Guidelines

Recommended Rate: 0.5-1 kg (1-2 lbs) per week is considered safe and sustainable for most people
Minimum Calories: Don't go below 1,200 calories/day for women or 1,500 calories/day for men without medical supervision
Maximum Deficit: Avoid deficits larger than 1,000 calories/day as they can slow metabolism and cause muscle loss
Adjust as Needed: As you lose weight, your TDEE decreases, so recalculate every 5-10 pounds lost
Listen to Your Body: If you feel extremely fatigued or hungry, your deficit may be too aggressive

Tips for Success

Use our TDEE Calculator to understand your maintenance calories in detail
Track your food intake consistently using Cal AI's AI-powered food recognition
Weigh yourself regularly (same time, same conditions) to monitor progress
Include strength training to preserve muscle mass during weight loss
Be patient - sustainable weight loss takes time but creates lasting results
Stay hydrated and prioritize protein to maintain satiety
Plan for occasional higher calorie days to maintain adherence long-term

When to Consult a Professional

If you have any underlying health conditions or take medications
If you're pregnant, breastfeeding, or planning to become pregnant
If you have a history of eating disorders
If you're under 18 or over 65 years old
If you need to lose a significant amount of weight (more than 50 lbs)

A registered dietitian or physician can provide personalized guidance for your specific situation.

Frequently Asked Questions

What calorie deficit is best for weight loss?

A deficit of 500 calories per day is widely recommended, resulting in about 0.5 kg (1 lb) lost per week. Aggressive deficits (750-1000 cal) lose weight faster but risk muscle loss and are harder to sustain.

How do I know if my calorie deficit is too large?

Signs of an excessive deficit include constant hunger, low energy, poor sleep, irritability, hair loss, and loss of menstrual cycle (women). If you experience these, increase your calories by 200-300 per day.

Should I eat back calories burned from exercise?

Generally, eat back about half of exercise calories. Fitness trackers tend to overestimate calorie burn by 20-50%. If you're very active, eating back some exercise calories prevents too large a deficit.

Calorie Deficit Calculator

Personal Information

Body Measurements

Activity Level

Desired Weight Loss Rate

Your Calorie Deficit Plan

Your Weight Loss Timeline