This section covers the arithmetic that comes up around training and competing: 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, or turning a raw box-score number into the stat that gets quoted in a broadcast. That overlaps in places with the fitness calculators elsewhere on this site — both sections deal with heart rate and calories burned, for instance — but the split is roughly this: the health section is about a body's own physiology (zones, VO2 max, resting metabolic rate), while this section is about performance on the clock or the bar — pace, splits, one-rep max, competition scoring — plus the kind of derived scoring stat that comes from a specific sport's own rulebook rather than general fitness.
Calculators in this section
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, adapted to what each activity actually measures (a treadmill's incline, a hike's elevation gain, a pool's 100 m unit). For race day specifically, the race pace calculator turns a target time for a standard distance 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 — it's a simplified approximation of the official World Masters Athletics tables, not a replacement for them.
Strength: one-rep max and competition scoring
The one-rep max calculator estimates a true 1RM from any weight-and-reps set using six published formulas (Epley, Brzycki, Lander, Lombardi, Mayhew, O'Conner), and works for any lift rather than one specific exercise. Next to it, the RPE calculator does the same estimate from a felt effort rating instead of a formal max-effort set, 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 against each other, the Wilks and DOTS calculators apply the two standard powerlifting normalization formulas — DOTS is the newer of the two and has replaced Wilks in a number of federations.
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 — easy to get wrong by hand, straightforward for a calculator built to expect it. Baseball has a deep bench of similar stats — batting average, WHIP, on-base percentage — and other sports have their own equivalents; this page will grow into more of them over time.