Fitness Calculators
Built on published sports science. Every formula is sourced, and the methodology is shown on each page.
Running
Pace conversions, training zones, and race time predictions.
- Pace Calculator
- Pace Estimator
- Race Predictor
Cycling
FTP from any test protocol, then power zones across five models including Coggan, Friel, and Polarized.
- FTP Calculator
- Power Zones
Swimming
Critical Swim Speed from 400m and 200m trials, or T-Pace from a 1000m effort, with training zones.
- CSS Calculator
- T-Pace Calculator
Strength
Estimate your one-rep max from any set and find the right weights for every training zone.
- 1RM Estimator
- Training Loads
Heart Rate
Five training zones from your max HR or age, with standard and Karvonen options.
- Standard Zones (%HRmax)
- Karvonen Zones (HRR)
Nutrition
Daily calorie and macro targets based on your stats, activity level, and goal.
- Macro Calculator
All tools are free and require no account. Formulas and sources are documented on each page.