Sport calculators

This section covers the arithmetic that comes up around training, competing and tracking fitness: how hard you are working right now, how much energy a session actually cost, converting a distance and a time into a pace or a finish-time prediction, working out how much weight is actually on the bar for a given rep count, and turning a raw score into the stat that gets quoted in a broadcast or logged on a handicap card.

Heart rate and aerobic effort

The maximum heart rate calculator and heart rate reserve calculator deal with what your heart is capable of; the target heart rate, heart rate zones and Zone 2 calculators turn that ceiling into the training zone a given effort falls into, using the Karvonen reserve method. The VO2 max calculator estimates aerobic capacity from a timed maximal-effort run rather than heart rate directly. None of these are lab measurements — they are published formulas (Tanaka's age-based maximum, Karvonen's reserve method, Cooper's run test) applied to figures you supply, most useful for comparing one session against another rather than treating any single output as exact.

Calories burned by activity

The running, cycling, swimming, hiking and weightlifting calorie calculators each apply a MET value specific to that activity against your body weight and the time spent doing it. Body weight drives these figures more than most people expect — the same pace or effort simply costs more energy in a heavier body — and a hard, short effort can burn a similar number of calories to a long, easy one while training completely different systems, which heart rate alone will not tell you apart.

Pace, speed and race time

The pace calculator and its per-activity variants — walking, hiking, swimming, treadmill and cycling — all solve the same underlying relationship between distance, time and speed. For race day specifically, the race pace calculator and half marathon pace calculator turn a target time into the pace needed to hit it, the race time predictor estimates a finish time at a new distance from a recent result using the Riegel formula, and the running split calculator breaks a target time into even checkpoints. The age grading calculator adds a rough age adjustment on top, so times can be compared loosely across different ages.

Strength: one-rep max and training load

The one-rep max calculator estimates a true 1RM from any weight-and-reps set using six published formulas, and the bench press 1RM calculator applies the same Epley formula to that one lift specifically. Next to them, the RPE calculator does the same estimate from a felt effort rating, the plate calculator works out which plates to load per side for a target bar weight, the strength-to-weight calculator expresses a lift as a multiple of bodyweight, and the training volume calculator adds up sets × reps × weight across a whole session. For comparing lifters of different bodyweights, the Wilks and DOTS calculators apply the two standard powerlifting normalization formulas.

Sport-specific stats

The baseball ERA calculator turns earned runs allowed and innings pitched into a pitcher's earned run average, handling the detail that innings-pitched is written in thirds (outs) rather than a clean decimal. The golf handicap calculator works out a single round's score differential using the World Handicap System formula. Other sports have their own equivalents; this page will grow into more of them over time.