Health & Fitness

Daily Calorie Needs Calculator

Estimates BMR with the Mifflin-St Jeor equation, then multiplies by an activity factor to give total daily calorie needs. Both BMR and daily needs are shown in whole kcal.

What this calculator does

The Daily Calorie Needs Calculator estimates your result instantly from the values you enter, using standard health & fitness formulas. Estimates BMR with the Mifflin-St Jeor equation, then multiplies by an activity factor to give total daily calorie needs. Both BMR and daily needs are shown in whole kcal. Calculations run in your browser, so nothing you type is sent to a server, and the output is an estimate rather than a certified or official figure.

Daily Calorie Needs Calculator

Result

—
BMR (kcal)
—
Daily Needs (kcal)

About Daily Calorie Needs Calculator

The Daily Calorie Needs Calculator estimates your basal metabolic rate with the Mifflin-St Jeor equation from sex, age, height and weight, then multiplies it by an activity multiplier (1.2 sedentary up to 1.9 athlete) to give total daily energy needs. Use it as a starting point for a calorie target.

Formula & Mathematical Calculation

BMR (kcal) = f(Sex, Age (years), Height (cm), Weight (kg), Activity)

Calculated according to standard health formulas implemented in the calculator core.

Calculation Example

For a male, age 30, 175 cm, 75 kg, activity Moderate (1.55): BMR = 10x75 + 6.25x175 - 5x30 + 5 = 1698.75, and 1698.75 x 1.55 = 2633.06. The tool shows BMR = 1699 kcal and Daily Needs = 2633 kcal.

Key Benefits

  • Uses the widely cited Mifflin-St Jeor equation for BMR
  • Applies a five-level activity multiplier from sedentary to athlete
  • Shows both BMR and total daily calorie needs side by side

How to Use this Calculator

  1. Choose sex and enter age
    Select Male or Female and type your age in years.
  2. Enter height, weight and activity
    Type height in cm and weight in kg, then choose an activity level from Sedentary to Athlete.
  3. Calculate
    Click Calculate and read the BMR (kcal) and Daily Needs (kcal) result boxes.

Assumptions & Limitations

What the calculation assumes

  • Every value you enter is treated as an exact, known amount.
  • Any rate or interval you enter is assumed to hold for the whole period unless the form asks for it separately.
  • Results use standard published formulas and account only for the values entered above.
  • Rounding is applied for display; the underlying calculation uses your full precision.
  • Results are returned in the same units you enter, unless the tool states the output unit.

What it does not cover

  • Daily Calorie Needs Calculator produces a calculated result for reference and learning, not a certified or official measurement.
  • Real-world outcomes differ when tolerances, rounding rules or local standards apply.
  • Definitions and standards vary by region and change over time; verify the convention that applies to your case.
  • Figures are only as accurate as the inputs you supply — check them before acting on the result.
  • For work where the result carries real consequences, confirm it against an authoritative source.

Frequently Asked Questions

The Mifflin-St Jeor equation: 10 x weight(kg) + 6.25 x height(cm) - 5 x age + 5 for males, or - 161 for females.

BMR is multiplied by the activity factor you select: 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 very active, or 1.9 athlete.

The Mifflin-St Jeor constant is +5 for male and -161 for female, so with all else equal a female estimate is 166 kcal lower at the BMR step.

Free to use, no account needed. Calculations run in your browser, so nothing you type is sent to a server. Results are estimates — how we build and check our calculators.