Daily Calorie Intake Calculator

Calculate your daily calorie needs based on age, gender, weight, height, and activity level.

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Daily Calorie Intake Calculator

Find out exactly how many calories you need per day to lose weight, gain weight, or maintain your current body — based on your age, sex, weight, height, and activity level. Uses the clinically validated Mifflin-St Jeor equation.

1,600–3,000
kcal/day typical adult range
−500 kcal
daily deficit for 0.5 kg/week loss
+300–500 kcal
daily surplus for lean muscle gain

What Is a Daily Calorie Intake Calculator?

A daily calorie intake calculator estimates the number of kilocalories (kcal) your body needs every 24 hours. It takes your personal stats — age, sex, body weight, height, and how active you are — and produces a target number you can use to guide your eating.

Unlike generic guidelines that suggest "2,000 calories a day," a personalised calorie calculator accounts for the fact that a 25-year-old male gym-goer weighing 90 kg and a 55-year-old sedentary woman weighing 65 kg have very different energy needs. Our calculator works in two steps:

  1. BMR (Basal Metabolic Rate) — the calories your body burns at complete rest just to keep you alive.
  2. TDEE (Total Daily Energy Expenditure) — your BMR scaled up by your actual daily activity level, giving your real-world calorie requirement.

Your goal — weight loss, maintenance, or weight gain — then shifts that TDEE number up or down to give your target daily calorie intake.

How Many Calories Do I Need Per Day?

The answer depends on five main factors. Here is what the research says about typical calorie requirements by demographic:

Group Sedentary Moderately Active Very Active
Women aged 19–30 1,800–2,000 2,000–2,200 2,400
Women aged 31–50 1,800 2,000 2,200
Women aged 51+ 1,600 1,800 2,000–2,200
Men aged 19–30 2,400–2,600 2,600–2,800 3,000
Men aged 31–50 2,200–2,400 2,400–2,600 2,800–3,000
Men aged 51+ 2,000–2,200 2,200–2,400 2,400–2,800

Source: Dietary Guidelines for Americans 2020–2025. Values in kcal/day. These are population averages — use our calculator for your personal calorie requirement.

Understanding BMR — Your Basal Metabolic Rate

Basal Metabolic Rate (BMR) is the minimum number of calories your body needs to keep essential systems running while you are completely at rest — breathing, blood circulation, temperature regulation, cell repair, and organ function. Think of it as your body's "idle fuel consumption."

BMR accounts for roughly 60–70% of your total daily calorie expenditure, making it the single biggest driver of how many calories you need. Several factors influence your BMR:

🏋️
Lean Muscle Mass
Muscle tissue burns ~3× more calories at rest than fat tissue. More muscle = higher BMR.
📅
Age
BMR declines ~1–2% per decade after age 30, partly due to muscle loss (sarcopenia).
⚧️
Biological Sex
Men typically have higher BMR due to greater average muscle mass and lower body fat percentage.
🫀
Hormones
Thyroid hormones directly regulate metabolic rate. Conditions like hypothyroidism lower BMR significantly.
Mifflin-St Jeor Equation (most accurate BMR formula)
For Men:
BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
For Women:
BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

TDEE — Your Total Daily Energy Expenditure

TDEE is the total number of calories you burn in a day, including BMR plus all physical activity. It is calculated by multiplying your BMR by an activity multiplier:

Activity Level Description Multiplier
Sedentary Desk job, little to no exercise × 1.2
Lightly Active Light exercise or sport 1–3 days/week × 1.375
Moderately Active Moderate exercise 3–5 days/week × 1.55
Very Active Hard exercise 6–7 days/week × 1.725
Extremely Active Athlete-level training or physical job + training × 1.9
Example: A 30-year-old woman, 65 kg, 165 cm, moderately active:
BMR = (10×65) + (6.25×165) − (5×30) − 161 = 1,426 kcal
TDEE = 1,426 × 1.55 = ~2,210 kcal/day

Calorie Requirements by Goal: Weight Loss, Maintenance, and Weight Gain

📉

Calorie Intake for Weight Loss

Consume 500 kcal below your TDEE for approximately 0.5 kg (1 lb) of fat loss per week. A 1,000 kcal deficit targets ~1 kg/week.

⚠️ Do not go below 1,200 kcal/day (women) or 1,500 kcal/day (men) without medical supervision.
⚖️

Calorie Intake to Maintain Weight

Eat at your TDEE. Energy in equals energy out. This is also called your daily calorie allowance or maintenance calories.

✅ Best starting point before adjusting for any specific fitness goal.
📈

Calorie Intake for Weight Gain

Eat 300–500 kcal above TDEE for lean muscle building. Higher surpluses (500–1,000 kcal) for faster (but fattier) bulk.

💪 Pair with progressive resistance training for optimal muscle gain results.

Calorie Requirements by Weight and Height

Your body weight and height are critical inputs for calculating your calorie needs, because they directly determine your BMR. Heavier individuals generally need more calories to sustain their mass, though body composition (ratio of muscle to fat) matters enormously.

Here are estimated daily calorie needs by weight for a moderately active 35-year-old man (170 cm) and woman (163 cm):

Body Weight Male (kcal/day) Female (kcal/day)
50 kg (110 lb)1,9201,740
60 kg (132 lb)2,0751,895
70 kg (154 lb)2,2302,050
80 kg (176 lb)2,3852,205
90 kg (198 lb)2,5402,360
100 kg (220 lb)2,6952,515

Values are approximate TDEE for moderately active adults (×1.55 activity multiplier). Use our calculator above for a personalised result.

Macronutrients: How to Split Your Daily Calorie Allowance

Knowing your daily calorie allowance is the first step. The second is distributing those calories across the three macronutrients — protein, carbohydrates, and fat — in a ratio that supports your goals.

🥩
Protein
4 kcal/g
25–35% of calories. Supports muscle repair, satiety, immune function. Target 1.6–2.2 g/kg body weight for active individuals.
🍞
Carbohydrates
4 kcal/g
40–55% of calories. Primary energy source, especially for the brain and high-intensity exercise. Prioritise whole grains and fibre.
🥑
Fats
9 kcal/g
20–35% of calories. Essential for hormones, vitamin absorption, and brain health. Choose unsaturated fats from nuts, fish, and oils.
Practical tip: For a 2,000 kcal/day intake with a 30/40/30 protein/carb/fat split:
  • Protein: 600 kcal ÷ 4 = 150 g
  • Carbohydrates: 800 kcal ÷ 4 = 200 g
  • Fat: 600 kcal ÷ 9 = 67 g

How to Use This Calorie Calculator — Step by Step

1
Enter your age

BMR decreases with age due to hormonal changes and gradual muscle loss. Enter your current age in years.

2
Select your sex

Male and female bodies have different BMR baselines. The calculator uses different formula constants for each.

3
Enter weight and height

Use your current body weight in kg and height in cm. You can weigh yourself first thing in the morning for the most consistent reading.

4
Choose your activity level honestly

Most people overestimate how active they are. If you're unsure, choose the level below what feels right. Sedentary is very common for office workers even if they exercise 3 times a week.

5
Select your goal and calculate

Choose weight loss (−500 kcal), maintenance, or weight gain (+500 kcal). Click Calculate to get your personalised daily calorie target.

Practical Tips to Hit Your Daily Calorie Intake Target

Getting your calorie number is step one. Here's how to actually achieve it consistently:

🍽️ Track your food for 2–4 weeks
Use a food diary or app to log meals. Research shows that people who track calories lose significantly more weight. You don't need to track forever — just long enough to build portion intuition.
🥗 Fill half your plate with vegetables
Vegetables are low-calorie and high-volume. They increase satiety without significantly impacting your caloric intake, making it easier to stay within your daily calorie allowance.
⏰ Use meal timing strategically
Front-loading calories earlier in the day is associated with better weight management. Eating a larger breakfast reduces hunger throughout the day, making it easier to avoid overeating.
💧 Drink water before meals
Drinking 500 ml of water 30 minutes before eating can reduce meal-time calorie intake by up to 13% in some studies by increasing feelings of fullness.
🔄 Recalculate as your weight changes
As you lose or gain weight, your BMR changes. Recalculate your daily calorie needs every 4–6 weeks or when your weight changes by 3–5 kg.
🏃 Increase NEAT activity
Non-Exercise Activity Thermogenesis (NEAT) — fidgeting, walking, standing — can contribute 200–600 extra calories burned per day. Take the stairs, walk during calls, and avoid prolonged sitting.

Frequently Asked Questions

How many calories should I eat per day to lose weight? +

To lose weight, you need to eat fewer calories than you burn (a calorie deficit). A daily deficit of 500 kcal below your TDEE creates a safe, sustainable rate of fat loss — approximately 0.5 kg (1 lb) per week. Start by calculating your TDEE with our calculator, then subtract 500. Never go below 1,200 kcal/day for women or 1,500 kcal/day for men without medical supervision, as very low calorie diets risk nutrient deficiencies and muscle loss.

How many calories do I need to gain weight and build muscle? +

For lean muscle building, aim for a 300–500 kcal surplus above your TDEE per day. This gives your body enough energy to synthesise new muscle tissue, especially when combined with progressive resistance training and adequate protein intake (1.6–2.2 g per kg body weight). A larger surplus (500–1,000 kcal) will result in faster weight gain but with a greater proportion of fat.

What is the difference between kcal and calories? +

In everyday nutrition, "calories" and "kcal" (kilocalories) mean the same thing. When a food label says 250 calories, it means 250 kcal. Technically, 1 kcal = 1,000 calories (the small calorie unit), but food labelling worldwide uses "calorie" to mean kilocalorie. So when our calculator gives you a number in "calories per day," it means kcal/day.

How accurate is an online calorie intake calculator? +

The Mifflin-St Jeor equation used in our calculator is considered the most accurate predictive equation for most people, with studies showing it estimates RMR within 10% for up to 82% of the population. However, individual variation exists — factors like gut microbiome, hormonal health, and genetics affect actual metabolism. Use the calculator result as a starting target and adjust by ±100–200 kcal based on your real-world weight changes after 2–3 weeks.

Can I use this calculator to calculate my kcal needs in kilojoules? +

Yes. To convert kcal to kilojoules (kJ), simply multiply by 4.184. For example, if your daily calorie need is 2,000 kcal, that equals 2,000 × 4.184 = 8,368 kJ. Kilojoules are the standard energy unit used on food labels in Australia, New Zealand, and some European countries.

How many calories per day for a woman trying to lose weight? +

The right number is unique to every woman, but a general rule: most women need 1,400–1,800 kcal/day for steady, sustainable weight loss. Sedentary women may lose weight at 1,400–1,600 kcal/day, while active women may need 1,700–2,000 kcal to lose weight while maintaining energy for workouts. Use the calculator above, then subtract 500 from your maintenance figure for a personalised target.

📋 Medical Disclaimer

The calorie estimates provided by this calculator are for informational purposes only. They are based on population-average predictive equations and may not precisely reflect your individual metabolic rate. Results should not be used as a substitute for advice from a registered dietitian, nutritionist, or qualified healthcare professional — particularly if you have an existing health condition, are pregnant or breastfeeding, or have a history of disordered eating. Always consult a healthcare provider before making significant changes to your diet.

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