Science-Backed · Mifflin-St Jeor Equation

Find Your Maintenance Calories
in 30 Seconds

Calculate your exact TDEE — the calories your body needs to maintain weight — using the formula trusted by nutrition dietitians.

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Imperial & Metric
Instant Results
BMR + TDEE Breakdown
Your Results
Maintenance Calories (TDEE)
calories / day
BMR (at rest)
kcal / day
Activity Level
multiplier
Weight Loss (–500)
kcal / day
Weight Gain (+300)
kcal / day

Results are estimates. Individual metabolism, body composition, and health conditions may vary. Consult a healthcare professional for personalised advice.

1990
Year Mifflin-St Jeor published
±10%
Accuracy for most individuals
5
Activity levels supported
Free
Always, no login needed
The Science

How Maintenance Calories Are Calculated

Two steps, one formula trusted by the Academy of Nutrition and Dietetics.

Step 01

Calculate Your BMR

Basal Metabolic Rate is how many calories your body burns at complete rest to sustain vital functions — breathing, circulation, cell repair.

Step 02

Apply Activity Multiplier

Your BMR is multiplied by a Physical Activity Level (PAL) factor, ranging from 1.2 (sedentary) to 1.9 (extra active) to get your TDEE.

Step 03

Interpret Your TDEE

Your TDEE is your maintenance calorie intake. Eat below it to lose weight, above it to gain, or at it to maintain your current body weight.

The Formula

Mifflin-St Jeor Equation

Men: (10 × kg) + (6.25 × cm) − (5 × age) + 5
Women: (10 × kg) + (6.25 × cm) − (5 × age) − 161

FAQ

Frequently Asked Questions

Everything you need to know about maintenance calories and TDEE.

What are maintenance calories?

Maintenance calories (TDEE — Total Daily Energy Expenditure) is the total number of calories your body burns in a day, accounting for both your resting metabolism and all physical activity. Eating at your maintenance level means your weight stays stable.

How accurate is this calculator?

The Mifflin-St Jeor equation is considered the gold-standard for estimating BMR and is accurate within roughly 10% for most healthy adults. Factors like unusual muscle mass, medical conditions, or hormonal imbalances can affect accuracy. Use it as a strong starting point, then adjust based on real results over 2–4 weeks.

How is TDEE different from BMR?

BMR (Basal Metabolic Rate) only counts calories burned at complete rest. TDEE (Total Daily Energy Expenditure) adds all the calories you burn through daily movement, exercise, and daily activities — making it a much more accurate reflection of your actual daily needs.

How many calories should I eat to lose weight?

A moderate deficit of 300–500 calories below your TDEE is widely recommended for sustainable fat loss — roughly 0.5–1 lb (0.25–0.5 kg) per week. Avoid going below 1,200 kcal/day for women or 1,500 kcal/day for men, as this can be counterproductive to health.

Do maintenance calories change over time?

Yes. As your weight, body composition, or activity level changes, your TDEE changes too. It's a good idea to recalculate every 4–8 weeks, or whenever your lifestyle changes significantly.

Should I use the metric or imperial option?

Either is fine — both produce identical results. Choose the unit system you're most familiar with for the most accurate inputs. The calculator automatically converts your values internally.

From the Blog

Practical guides to help you understand and use your maintenance calorie number.