Elevate Your Fitness Engineering
Unlock precision with our collection of specialized fitness calculators and tools. Designed for those who demand accuracy in their journey to greatness.
BMI Calculator
Determine your body mass index based on weight and height to assess weight category.
Macro Calculator
Calculate your optimal protein, carbohydrate, and fat intake for your specific fitness goals.
Calorie Burn
Estimate calories burned during various physical activities.
Hydration Plan
Get personalized daily water intake recommendations.
HIIT Timer
Programmable Tabata and HIIT interval timer for training.
HR Zones
Calculate your heart rate zones for targeted cardio training.
One Rep Max (1RM)
Estimate your maximum lifting capacity for any exercise based on sub-maximal efforts.
Body Fat Estimator
Use the US Navy method to estimate your body fat percentage with simple tape measurements.
Fitness is an Engineering Problem
At Fitness Gen, we treat your body as a high-performance system. Most fitness journeys fail not because of lack of effort, but because of a lack of precision. Our tools bridge the gap between effort and results.
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Mathematical Modeling
We utilize the same algorithms used by military and clinical sports scientists to predict performance and recovery needs.
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Frictionless Experience
Zero sign-ups. Zero ads. Just pure, unadulterated computation that respects your focus and your time.
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Privacy-First Compute
Your health data is yours. Calculations happen in your browser, never touching a database.
Precision
Insights
Frequently asked questions about our tools and the science behind them.
How accurate is the 1RM?
The Brzycki formula we use is highly accurate for reps under 10. For reps higher than 10, the accuracy begins to diminish as fatigue models shift.
Why US Navy Body Fat?
The US Navy method is one of the most reliable tape-measure methods available, often correlating within 3-4% of DEXA scans when performed correctly.
MET Values and Calories
MET (Metabolic Equivalent of Task) is the gold standard for clinical energy expenditure estimation, accounting for intensity across varied body weights.
Mifflin-St Jeor vs others?
We utilize the Mifflin-St Jeor equation for macros as it has been scientifically proven to be more accurate for the modern, non-clinical population than the older Harris-Benedict model.