About TDEE Calculator
We built this site because most calorie calculators online are either too simple to be useful or too complicated to actually use. You get a number with no context and no idea what to do next. That needed to change.
Make accurate nutrition free for everyone.
Give every person a medically grounded, easy to use tool that shows them exactly how many calories their body needs. No paid plans. No misleading numbers. No supplement upsells.
The science has been published for decades. We just built the cleanest, most accurate version of it we could.
Medically grounded
Built on peer-reviewed equations used in clinical practice today.
Free, forever
No paid plans, no accounts, no supplement upsells. Ever.
Honest numbers
Outputs depend only on your inputs — never on advertisers.
The Calculators on This Site
Every tool here is free, fast, and built on the same evidence-based foundation.
The Formulas We Use and Why
Many calculators online never tell you which formula they use. That is a real problem because different formulas produce meaningfully different results.
Mifflin-St Jeor
Our primary formula. Published in 1990 and recommended by registered dietitians in clinical practice today. A 2005 study in the Journal of the American Dietetic Association confirmed it outperforms Harris-Benedict in accuracy across diverse populations.
Harris-Benedict
The original BMR equation, developed in 1919 and revised in 1984. Available as an alternative for comparison. Tends to overestimate slightly, particularly at higher body weights.
Katch-McArdle
Used when body fat percentage is known. More accurate for lean individuals and athletes because it factors in lean body mass directly.
Activity Multipliers
Derived from doubly labeled water studies, the gold standard for measuring real-world energy expenditure. Ranges from 1.2 for sedentary individuals to 1.9 for very high activity levels.
Where Our Information Comes From
Every claim, formula, and recommendation traces back to published research or established clinical guidelines.
Primary sources include the American Journal of Clinical Nutrition, Journal of the Academy of Nutrition and Dietetics, Obesity Reviews, WHO dietary reference values, and NIH body weight guidelines.
No sponsored content. No advertiser influences our outputs. The numbers you get are based purely on the formula inputs you provide.
Why You Can Trust These Numbers
Clinical background
The person behind this site holds an MPhil in Pharmacology with years of patient-facing experience. This is not a fitness blogger running numbers through a spreadsheet.
Formula transparency
We tell you exactly which equation we use and why. You can verify it yourself.
No financial conflicts
We do not sell supplements, coaching, or meal plans.
Safe recommendations
Deficit targets stay within clinically safe ranges. We flag when calorie levels drop below thresholds that could cause harm.
Regular updates
When new research changes best practice, the content gets updated to reflect it.
A Note on Medical Advice
This calculator is an educational tool. It produces estimates based on validated population-level formulas. It does not know your medical history, medications, or any conditions affecting your metabolism.
If you have thyroid disease, PCOS, diabetes, a history of disordered eating, or any metabolic disorder, work with a registered dietitian or your physician before making significant changes to your calorie intake. The numbers here are a starting point, not a prescription.