Calories Maintenance Calculator

Calculate how many calories you need per day to maintain your current weight. Uses the Mifflin-St Jeor formula with activity-level adjustments and a balanced macro split.

Enter Your Details to Get Started

Fill in your age, height, weight, and activity level above, then hit Calculate.

Find Your Daily Maintenance Calories

Enter your age, height, weight, and activity level to calculate how many calories your body needs each day to maintain your current weight. Based on the Mifflin-St Jeor equation, the most accurate formula for resting metabolic rate.

BMR · TDEE · Macros

Why Use This Calculator?

Mifflin-St Jeor Formula

Uses the most widely recommended equation for estimating basal metabolic rate, trusted by dietitians and sports nutritionists worldwide.

Activity-Adjusted TDEE

Applies a research-backed activity multiplier to your BMR so the result reflects your actual daily energy expenditure, not just resting calories.

Balanced Macro Split

Shows a suggested 30/40/30 protein-carb-fat ratio converted into grams per day, giving you a practical starting point for meal planning.

Metric & Imperial Support

Enter your height in centimeters or feet/inches and your weight in kilograms or pounds — the calculator handles the conversion internally.

How this Calories Maintenance Calculator works

This maintenance calorie calculator determines the exact number of calories your body needs each day to sustain its current weight. The calculation begins by estimating your Basal Metabolic Rate (BMR) — the calories you burn at complete rest just to keep your organs functioning — using the Mifflin-St Jeor equation, which is widely regarded by dietitians as the most accurate formula for modern populations.

Once your BMR is established based on your age, gender, height, and weight, the tool applies an activity multiplier corresponding to the lifestyle level you select. This ranges from a sedentary 1.2 multiplier for desk jobs with little exercise, up to a 1.9 multiplier for intense daily workouts or heavy physical labor. The resulting Total Daily Energy Expenditure (TDEE) is your maintenance target.

The calculator also provides a practical macro breakdown, dividing your maintenance calories into a balanced 30/40/30 ratio of protein, carbohydrates, and fats. Because all calculations are performed locally in your browser using JavaScript, your personal physical metrics are never transmitted to any external server.

How to use this Calories Maintenance Calculator

1

Enter your details

Select your gender, enter your age, height, and weight using metric or imperial units.

2

Set activity level

Choose the option that best matches how often and how intensely you exercise during a typical week.

3

Get your result

Hit Calculate to see your BMR, daily maintenance calories (TDEE), and a balanced macro breakdown.

Example Usage

Calculating maintenance calories for a 30-year-old male:

Input
Gender: Male Age: 30 Height: 175 cm Weight: 75 kg Activity: Moderately Active
Output
BMR: 1,673 cal/day TDEE: 2,593 cal/day Protein: 195g | Carbs: 259g | Fats: 86g

Frequently Asked Questions

What are maintenance calories?
Maintenance calories are the number of calories your body needs each day to keep your weight stable — not gaining or losing. It accounts for your basal metabolic rate plus the energy burned through daily activity and exercise.
What formula does this calculator use?
It uses the Mifflin-St Jeor equation, which is considered the most accurate predictor of resting metabolic rate by the Academy of Nutrition and Dietetics. For men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 5. For women the constant changes to −161.
How accurate is the TDEE estimate?
The Mifflin-St Jeor formula estimates BMR within roughly 10% for most people. The activity multiplier adds another variable, so treat the TDEE number as a starting estimate. Track your weight over 2–3 weeks and adjust by 100–200 calories if the scale moves in an unwanted direction.
What activity level should I choose?
Pick the level that reflects your average week over the past month. If you sit most of the day but hit the gym three times a week, "Moderately Active" is a reasonable choice. If you have a physically demanding job on top of gym sessions, go with "Very Active" or "Extra Active."
What does the 30/40/30 macro split mean?
30% of your daily calories from protein, 40% from carbohydrates, and 30% from fats. The calculator converts these percentages into grams. This ratio is a balanced starting point, but individuals with specific goals (muscle gain, endurance sports) may need adjustments.
Should I eat exactly this many calories every day?
Not necessarily. Daily intake naturally fluctuates. Focus on your weekly average rather than hitting the exact number each day. Consistency over time matters more than precision on a single day.
Is BMR different from TDEE?
Yes. BMR (Basal Metabolic Rate) is the energy your body uses at complete rest — breathing, circulation, cell repair. TDEE (Total Daily Energy Expenditure) adds the calories you burn through movement and exercise on top of BMR.
Can I use this calculator if I want to lose or gain weight?
Yes. Once you know your maintenance calories, subtract 300–500 calories for gradual weight loss or add 300–500 for weight gain. This calculator focuses on the maintenance baseline; the existing Calorie Calculator on CodeItBro covers deficit and surplus goals in more detail.
Does age affect maintenance calories?
Yes. Metabolic rate typically decreases with age because of reduced muscle mass and hormonal changes. The Mifflin-St Jeor formula subtracts 5 calories per year of age to account for this gradual decline.
Is my data stored or sent anywhere?
No. Every calculation runs locally in your browser. Nothing you enter — age, weight, height, or any other detail — is transmitted to a server or stored anywhere.

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