Cernarus

Daily Calorie Intake Calculator

This calculator estimates daily calorie needs using multiple peer-accepted formulas (Mifflin–St Jeor, revised Harris–Benedict, and Katch–McArdle). Select the method that best fits your available data and preferences.

Use age, sex, weight, height, activity level, and an adjustable goal (maintain, deficit, or surplus). Optional body fat percentage lets the Katch–McArdle method compute energy needs from lean mass.

Updated Nov 8, 2025

Baseline metabolic rate using the Mifflin–St Jeor equation, then scaled by activity factor and adjusted for weight-change goal.

Inputs

Results

Updates as you type

Estimated TDEE

1,742

Daily calories for selected goal

1,742

OutputValueUnit
Estimated TDEE1,742kcal
Daily calories for selected goal1,742kcal
Primary result1,742

Visualization

Methodology

Equations implemented are standard published formulas for basal metabolic rate (BMR). BMR is multiplied by an activity factor to produce Total Daily Energy Expenditure (TDEE). The final recommendation applies a goal adjustment (percentage deficit or surplus).

We follow software and quality guidance to help ensure reliability: validate inputs, enforce reasonable min/max ranges, and flag missing required values for each method. See citations for standards on software validation and medical device/software quality.

Further resources

External guidance

Expert Q&A

Which method should I choose?

If you know your body fat percentage, Katch–McArdle can be more personalized. Mifflin–St Jeor is recommended for general population estimates. Harris–Benedict is an acceptable alternative. All are estimates and should be combined with monitoring.

How accurate are these numbers?

These are population-level estimates and can vary per individual by ±10–20% or more. Use them as starting points, then track weight and composition changes and adjust. See accuracy and standards notes in citations.

Can I use this if I have a medical condition?

This tool does not replace medical or dietetic advice. Consult a healthcare professional for conditions that affect metabolism, such as thyroid disorders, recent surgery, or pregnancy.

Why enforce input ranges?

Input range checks reduce the risk of nonsensical outputs and help meet basic software safety and usability expectations as recommended by engineering standards.

Sources & citations

  • National Institute of Standards and Technology (NIST) — Software and Systems Validation Guidance https://www.nist.gov
  • International Organization for Standardization (ISO) — Quality and safety standards for health software https://www.iso.org
  • IEEE — Standards for software engineering and system safety best-practices https://www.ieee.org
  • Occupational Safety and Health Administration (OSHA) — Guidance on safety and human-factors considerations https://www.osha.gov