Calculator Suite

Free Calorie Calculator | Calculate Daily Calories & BMR Online

Calculate your daily calorie needs with our free, accurate calorie calculator. Find your BMR, TDEE, and personalized nutrition goals for weight loss or muscle gain

Personal Information
Enter your details to calculate your daily calorie needs

Biological sex affects BMR calculation

Age affects metabolic rate

Current body weight

Height in selected unit

Select the option that best describes your daily activity

What you want to achieve with your diet

Mifflin-St Jeor is more accurate for most people

Quick Presets

How this calculator works
Method, formula, examples, assumptions, and review notes for this calculator.

How this calculator works

  • The calculator estimates resting energy needs with the Mifflin-St Jeor equation.
  • It multiplies BMR by an activity factor to estimate total daily energy expenditure.
  • Goal calories are calculated by applying a selected deficit or surplus to the maintenance estimate.

Formula

Mifflin-St Jeor resting energy estimate

BMR=10W+6.25H−5A+SBMR = 10W + 6.25H - 5A + S

Plain text formula: BMR = 10 x weight in kg + 6.25 x height in cm - 5 x age + sex adjustment; TDEE = BMR x activity factor.

W = weight in kilograms
H = height in centimeters
A = age in years
S = sex adjustment: +5 for male, -161 for female in the Mifflin-St Jeor equation

Worked examples

Maintenance estimate

Inputs

  • Female
  • Age: 35
  • Height: 165 cm
  • Weight: 68 kg
  • Activity: lightly active

Calculation

  • BMR = 10 x 68 + 6.25 x 165 - 5 x 35 - 161 = about 1,375 kcal/day.
  • With a lightly active factor, TDEE is about 1,890 kcal/day.

The TDEE estimate is a starting point for tracking; real maintenance should be adjusted using weight trends and health context.

Curated video guide
Selected YouTube lessons that add context after the calculator, formulas, examples, assumptions, and limitations.

Basal and Total Metabolic Rate - Mifflin St. Jeor Equations

Source: Vivo Phys - Evan Matthews on YouTube

Why this video: Selected because it explains BMR and total metabolic rate equations in an educational physiology context without diet marketing.

What it adds: It complements the calculator's Mifflin-St Jeor formula and activity multiplier assumptions.

Use with this calculator: Run the calculator with your inputs, then use the video to understand why BMR and TDEE are separate estimates.

Limits: The video and calculator are educational estimates only and do not replace clinical nutrition, medical, or athletic guidance.

How to interpret your result

  • Use the output as a planning baseline and compare it with actual weight and energy trends over several weeks.
  • Very low calorie targets can be unsafe or unsustainable and should be reviewed with a qualified professional.

Assumptions

  • The entered activity level represents average weekly activity.
  • The Mifflin-St Jeor equation is used as an estimate for adults.
  • Food intake and body weight are measured consistently when adjusting targets.

Limitations

  • Equations estimate average needs and can differ from measured metabolic rate.
  • The calculator does not account for pregnancy, lactation, illness, medications, or athletic training demands.
  • Macronutrient splits are planning estimates, not clinical nutrition prescriptions.

Common mistakes

  • Double-counting exercise calories when activity has already been included.
  • Using the target as a fixed rule instead of adjusting to observed trends.
  • Setting aggressive deficits that are hard to maintain or medically inappropriate.

Sources

Mifflin et al. 1990 resting energy equation, PubMedNational Academies: Dietary Reference Intakes for Energy

Disclaimer

Last updated and reviewed by

Updated 2026-06-06Calculator Suite editorial review