About These Calculators
Science-based fitness calculators to help you reach your health goals. Calculate your TDEE, figure out macro splits, estimate body fat percentage, plan running paces, and more — all using peer-reviewed formulas.
Fitness & Health Calculators
18 toolsBody Fat Calculator (Navy Method)
Estimate your body fat percentage using the U.S. Navy method
TDEE Calculator
Calculate your Total Daily Energy Expenditure and BMR
Macro Calculator
Calculate your daily protein, fat, and carb targets
Calorie Deficit Calculator
Find out exactly how many calories to eat to reach your goal weight
One Rep Max Calculator
Estimate your one-rep max using multiple proven formulas
Plate Loading Calculator
Find the exact plate combination for any barbell weight
Wilks Score Calculator
Calculate your Wilks score for powerlifting competitions
Running Pace Calculator
Calculate pace, time, or distance for any run
Race Time Predictor
Predict your race time at any distance using the Riegel formula
Protein Intake Calculator
Find your optimal daily protein intake based on your goals
Water Intake Calculator
Calculate your optimal daily water intake based on your body and activity level
Pregnancy Due Date Calculator
Calculate your estimated due date from your last menstrual period or conception date
Sleep Cycle Calculator
Wake up refreshed by timing your sleep cycles perfectly
BAC Calculator
Estimate your blood alcohol content using the Widmark formula
BMR Calculator
Calculate your basal metabolic rate using the Mifflin-St Jeor equation
Lean Body Mass Calculator
Calculate your lean body mass from weight and body fat percentage
Heart Rate Zone Calculator
Find your 5 heart rate training zones for optimal fitness
Intermittent Fasting Calculator
Plan your fasting and eating windows for any IF protocol
Frequently Asked Questions
Are these fitness & health calculators free?
Yes, all 18 calculators are completely free with no signup required. They run entirely in your browser — no data is sent to any server.
How accurate are these calculators?
Our calculators use industry-standard formulas and are regularly updated. However, they provide estimates — always verify critical calculations with a professional in the relevant field.
Can I use these calculators on my phone?
Yes, all calculators are mobile-responsive and work on any device with a web browser. No app download needed.
Do you save my calculations?
No. All calculations happen in your browser. We don't store any of your inputs or results. Your data stays on your device.
Can I embed these calculators on my website?
Select calculators offer embed codes that you can copy and paste into your website or blog. Look for the "Embed This Calculator" section on individual tool pages.