Calorie Calculator – TDEE, Calorie Deficit & Daily Intake
Use this free calorie calculator as a TDEE calculator, calorie deficit calculator for weight loss, or maintenance calorie calculator. Enter your age, height, weight, and activity level for a personalized daily calorie target.
Calorie Calculator
This free calorie calculator estimates your daily calorie needs using the Mifflin-St Jeor equation. It is the formula recommended by the Academy of Nutrition and Dietetics as the most accurate for the general population. Enter your age, height, weight, gender, and activity level to get a personalized daily calorie target for weight loss, weight gain, or maintenance. Whether you need a TDEE calculator, a calorie deficit calculator, or a maintenance calorie calculator, this calories calculator covers all three goals in one place.
What Are Calories?
A calorie is a unit of energy. The human body requires calories to carry out every process from breathing and circulating blood to digesting food and moving muscles. Even at complete rest, the body burns calories to keep organs functioning. This resting energy use is called the Basal Metabolic Rate (BMR).
The World Health Organization (WHO) defines energy intake from food as the total calories consumed from carbohydrates, proteins, fats, and alcohol. When calorie intake equals calorie expenditure over time, body weight remains stable. A sustained surplus leads to weight gain; a sustained deficit leads to weight loss.
Not all adults require the same number of calories. Age, sex, height, weight, and activity level all influence how many calories a person burns each day. A calorie intake calculator removes the guesswork by applying validated equations to your individual stats.
Calorie Calculator Formula — The Mifflin-St Jeor Equation
This calorie calculator uses the Mifflin-St Jeor equation to estimate Basal Metabolic Rate (BMR). It then multiplies BMR by an activity factor to calculate Total Daily Energy Expenditure (TDEE).
For men: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) + 5
For women: BMR = (10 x weight in kg) + (6.25 x height in cm) - (5 x age) - 161
TDEE = BMR x Activity Factor
| Activity Level | Description | Multiplier |
|---|---|---|
| Sedentary | Little or no exercise, desk job | 1.2 |
| Lightly Active | Light exercise 1-3 days per week | 1.375 |
| Moderately Active | Moderate exercise 3-5 days per week | 1.55 |
| Very Active | Hard exercise 6-7 days per week | 1.725 |
| Extremely Active | Very hard exercise or physical job daily | 1.9 |
Consider a 32-year-old woman, 165 cm tall, weighing 68 kg, who exercises moderately 4 days per week. Her BMR = 1,390 calories per day. Her TDEE = 1,390 x 1.55 = 2,155 calories per day. For weight loss with a 500 calorie deficit: target 1,655 calories per day.
How to Use This Calorie Calculator
- Select your unit system — metric (kg, cm) or imperial (lbs, ft)
- Enter your details — age, gender, height, and weight
- Choose your activity level — be honest; overestimating activity is the most common error
- Select your goal — lose weight, maintain weight, or gain weight — then click Calculate
Results show your BMR, TDEE, and adjusted daily calorie target based on your goal. The calculator also displays a calorie breakdown explaining how each number is derived.
Understanding Your Daily Calorie Results
This calories calculator returns three key numbers: BMR, TDEE, and Goal Calories. BMR represents calories burned at complete rest. TDEE covers total daily calories burned including all activity. Goal Calories is the adjusted target based on your weight loss, gain, or maintenance goal. TDEE is the most important number. Eating below TDEE creates a caloric deficit; eating above creates a caloric surplus.
Calorie Calculator for Weight Loss
A calorie calculator for weight loss works by applying a calorie deficit to the TDEE estimate. A deficit of 500 calories per day below TDEE creates a theoretical loss of approximately 0.45 kg (1 lb) of fat per week.
This calorie deficit calculator follows CDC guidelines on healthy weight loss. The CDC recommends a gradual weight loss of 0.5-1 kg per week as the safest and most sustainable approach. Rapid fat loss approaches often result in muscle loss and metabolic adaptation.
| Deficit Size | Weekly Fat Loss | Best For |
|---|---|---|
| 250 cal/day deficit | ~0.23 kg per week | Slow, sustainable cut |
| 500 cal/day deficit | ~0.45 kg per week | Standard weight loss — recommended |
| 750 cal/day deficit | ~0.68 kg per week | Faster loss; harder to sustain |
Research consistently shows that very low calorie intake causes serious problems. Consuming below 1,200 calories per day for women, or 1,500 for men, leads to muscle loss, nutrient deficiencies, and slowed metabolism. Knowing how many calories should I eat to lose weight safely requires calculating TDEE first and applying a moderate 300-500 calorie deficit. Knowing how many calories to lose weight safely is essential before starting any reduction plan.
Calorie Calculator to Gain Weight
A calorie calculator to gain weight applies a caloric surplus — consuming more than the TDEE. To add lean mass rather than fat, keep the surplus controlled. A 250-500 calorie surplus above TDEE per day supports muscle gain of approximately 0.25-0.5 kg per week when combined with resistance training.
For lean bulking, a surplus of 300-500 calories combined with adequate protein intake per NIH research on protein and muscle hypertrophy is the evidence-based approach. Understanding how many calories should I eat for weight gain requires calculating TDEE first.
| Surplus Size | Weekly Weight Gain | Best For |
|---|---|---|
| 250 cal/day surplus | ~0.2 kg per week | Lean bulk — minimal fat gain |
| 500 cal/day surplus | ~0.45 kg per week | Standard bulk |
| 750-1000 cal/day surplus | ~0.7-0.9 kg per week | Aggressive bulk |
Maintenance Calorie Calculator — Keeping Your Current Weight
The maintenance calorie calculator mode simply returns the TDEE value — the number of calories needed to maintain current body weight with no change. When calorie intake matches TDEE consistently over time, body composition remains stable.
Maintenance calories are not a fixed number. TDEE changes as weight, age, and activity level change. A person who loses 10 kg has a lower TDEE than before. Using this daily calorie intake calculator monthly helps track shifting energy needs.
How Many Calories Should I Eat a Day?
How many calories should I eat a day depends on age, sex, height, weight, and activity level. General population averages from the National Institutes of Health (NIH) provide a useful reference.
| Group | Sedentary | Moderately Active | Very Active |
|---|---|---|---|
| Women, age 19-30 | 2,000 cal | 2,200 cal | 2,400 cal |
| Women, age 31-50 | 1,800 cal | 2,000 cal | 2,200 cal |
| Women, age 51+ | 1,600 cal | 1,800 cal | 2,000-2,200 cal |
| Men, age 19-30 | 2,400 cal | 2,600-2,800 cal | 3,000 cal |
| Men, age 31-50 | 2,200 cal | 2,400-2,600 cal | 2,800-3,000 cal |
| Men, age 51+ | 2,000 cal | 2,200-2,400 cal | 2,400-2,800 cal |
How many calories do I need depends heavily on activity level and body composition goals. Use the calorie calculator above for a personalized estimate.
How to Calculate Calorie Deficit
Knowing how to calculate calorie deficit requires two numbers: TDEE (calories burned per day) and a target intake below that number.
- Calculate BMR using the Mifflin-St Jeor equation
- Multiply BMR by activity factor to get TDEE
- Subtract 300-500 calories from TDEE to set the deficit target
- Do not go below 1,200 cal (women) or 1,500 cal (men) regardless of the calculated deficit
- Reassess every 4 weeks — as weight drops, TDEE decreases, requiring a new calculation
A 28-year-old man, 180 cm, 90 kg, moderately active: BMR = 1,890 cal/day. TDEE = 1,890 x 1.55 = 2,930 cal/day. 500-calorie deficit target: 2,430 cal/day. Expected fat loss: ~0.45 kg per week. This calorie deficit to lose weight calculator automates every step. The TDEE calculator to lose weight approach works best when activity level is set honestly.
Macro Calculator — Protein, Carbs, and Fat
Once the daily calorie target is known, the next step is distributing those calories across the three macronutrients using a macro calculator. Protein provides 4 cal/g, carbohydrates provide 4 cal/g, and fat provides 9 cal/g.
| Goal | Protein | Carbohydrates | Fat |
|---|---|---|---|
| Weight loss | 30-40% | 30-40% | 20-30% |
| Muscle gain | 25-35% | 40-50% | 20-25% |
| Maintenance | 15-25% | 45-55% | 25-35% |
| Athletic performance | 20-30% | 50-60% | 20-30% |
Higher protein intake during a calorie deficit is critical for preserving lean muscle mass. The Harris-Benedict equation was an earlier BMR estimation method. Mifflin-St Jeor has since replaced it as the more accurate standard. Managing macronutrients alongside total calories produces better long-term outcomes than calorie counting alone.
Limitations of This Calorie Calculator
The Mifflin-St Jeor equation has a margin of error of approximately 10% for most healthy adults. Several factors reduce accuracy. These include high muscle mass (greater energy expenditure at rest), age-related metabolic decline in older adults, and metabolic conditions such as hypothyroidism. Activity overestimation and food label inaccuracy (up to 20% variance) are additional sources of error. This calculator provides a useful evidence-based estimate — not a medical measurement. Is 1200 calories a day enough? For most moderately active adults, 1,200 calories is an aggressive deficit and should only be used under medical supervision.
Practical Tips for Hitting Your Calorie Goal
- Track for 7 days before changing anything — understand current caloric intake before creating a deficit or surplus
- Use a food scale for the first 2 weeks — volume estimates are consistently inaccurate; weighing food eliminates a major source of error
- Prioritize protein at every meal — protein has the highest satiety per calorie. Its thermic effect burns 20-30% of its own calories during digestion
- Build in a weekly refeed for long-term deficits — one day at TDEE every 7-10 days helps maintain leptin levels and adherence
- Recalculate every 4-6 weeks — understanding what is TDEE and how it shifts is essential. A person who has lost 8 kg requires a new calorie target to continue progress
For a more complete health picture, use DigiCalc's BMR calculator to check your resting metabolic rate. Check your weight status with our BMI calculator. For those building muscle, the ideal weight calculator provides goal weight targets based on height and frame size.
For a full suite of health tools, visit DigiCalc's health calculators hub covering BMI, BMR, body fat, ideal weight, and water intake.