About CaloricLab
Free, accurate, science-backed nutrition calculators for everyone.
CaloricLab is a suite of free nutrition calculators designed to give you accurate, actionable numbers for your health and fitness goals.
Whether you're trying to lose fat, build muscle, or simply understand how your body works, our calculators provide the foundation you need — using the same peer-reviewed formulas trusted by registered dietitians and sports scientists.
Our Approach
There's a lot of noise in the nutrition world. Fad diets, conflicting advice, and overcomplicated systems leave most people more confused than when they started. CaloricLab cuts through that.
Give people the right numbers, explain the science clearly, and get out of the way.
We're not here to sell you a program or a supplement. We're here to give you the tools to make informed decisions.
The Science We Use
Mifflin-St Jeor
The most validated BMR equation for the general population. Used by default in all our calculators.
Katch-McArdle
More accurate when body fat % is known. Factors in lean mass instead of total body weight.
ISSN Protein Guidelines
Evidence-based targets from the International Society of Sports Nutrition for muscle building and fat loss.
ACSM Activity Multipliers
Established activity level factors used to convert BMR into your real-world daily calorie needs.
Completely Free
No account required, no email signups, no paywalls. All calculators are and will always be 100% free. We're supported by display advertising, not by selling your data.
Privacy First
Every calculation happens entirely in your browser. Your age, weight, height, and other health data never leaves your device. See our Privacy Policy.
Contact
Have a question, found an error, or want to suggest a new calculator? We'd love to hear from you. Reach us at mikeephelps@gmail.com.