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.