Guides
The charts and the reasoning behind the calculators. Each chart is computed from the formula its calculator uses, or reproduced from the published data it cites.
1RM percentage chart
50% to 100% of a one rep max, the reps Epley and Brzycki predict at each step, and where those predictions stop holding.
Running pace chart
Paces between 3:00 and 8:00 a kilometer, each with its mile pace and four race finish times.
Marathon pace chart
The pace to hold and the checkpoints to hit for fifteen goal times, two and a half hours up to six.
VO2max by age chart
Lab-measured averages for men and women at every age, and what a Cooper distance or 1.5-mile time converts to.
Zone 2 heart rate and zones by age
Zone 2 and every other zone in beats per minute across eleven ages, and what a resting pulse changes.
Race time equivalents
What a 5K result says about your mile, 10K, half and marathon, minute by minute.
Calories burned running chart
Energy per kilometer and per mile by body weight and speed, and what an incline adds.
Swim pace chart
Pace per 100 turned into finish times for pool and triathlon distances, meters and yards.