About AthleteCalcs
AthleteCalcs is a free set of calculators and quizzes for training and fitness: strength, running, cardio and endurance, military fitness tests, and body and nutrition.
Who runs this site
AthleteCalcs is run by Chris Jensen, an independent individual based in Florida. It is not a company. I started it because information people were looking for was missing or hard to find, and I wanted the numbers behind training and nutrition in simple tools that show their method. Where the site says “we”, that is me. You can reach me at rusticreckoner@gmail.com or through the contact page.
Why this site exists
Training advice is full of numbers: a percentage of your max, a pace per mile, a heart rate zone, a calorie target. Most of them come from a formula, and the formula usually has a name and a limit that the number alone does not show. AthleteCalcs puts the formula on the page next to the result, so you can see what an estimate is based on and how far to trust it.
What you will find here
There are 67 calculators in five groups, plus five short quizzes:
- Strength: one-rep max, bench press, deadlift and overhead press estimates, plate loading, percentage charts and strength standards
- Running: pace, race time prediction and pace conversion for the 5K, 10K, half marathon and marathon
- Cardio & Endurance: calories burned, heart rate zones, maximum heart rate, cycling power, rowing splits and steps
- Military Fitness Tests: simplified score estimators for the Army, Air Force and Marine Corps fitness tests, plus height, weight and body fat standards
- Body & Nutrition: BMI, BMR, body fat, calories, macros, deficits and bulking, with unit conversions
- Finders & Quizzes: short quizzes that help you place your body type, fitness level, military test, running plan and workout split
Where the numbers come from
Each calculator page lists the formula or standard it is based on. Examples are the Epley, Brzycki, Lombardi and O’Conner one-rep-max formulas, the Karvonen heart rate reserve method, the Mifflin equation for resting energy use, the World Health Organization’s waist-to-hip ratio categories and standard pace and unit-conversion arithmetic. Where a score table is simplified, such as the military fitness tests, the page says it is an approximation and not the official regulation table. The how we calculate page explains our approach and its limits.
What this site does not do
It does not give medical, nutrition or coaching advice, it is not an official scoring tool for any military branch and it does not replace a coach, trainer, doctor or dietitian. See the disclaimer for the details.
How the site is paid for
AthleteCalcs is free to use and is supported by advertising from Google AdSense. Advertising never changes a result. For how analytics and advertising cookies are handled, see the privacy policy.