Performance calculators
Deterministic fitness math for lifters and runners.
57 calculators for FFMI, DOTS, 1RM, VO2 max, Zone 2, race times, and recovery. Every formula sourced, every limit named.
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Pick your goal
Optimize Body Composition
Optimize body composition with calorie targets that preserve strength while dropping body fat.
Open →Build Strength & Muscle
Build muscle by translating your calorie target into macro and protein plans for strength gains.
Open →Benchmark Your Strength
Benchmark your lifts against DOTS, strength standards, and 1RM projections.
Open →Plan Your Race
Plan race pacing, dial in training paces, and calibrate heart rate zones for distance running.
Open →Recover Better
Recover better by aligning sleep, hydration, and intensity to improve training quality.
Open →Understand Body Composition
Understand body composition with simple estimates that track direction over time.
Open →Worth reading.
Long-form articles
Evidence-backed, sourced, dated.
Evidence-Based Hypertrophy & Powerlifting Programming 2026
Evidence-based hypertrophy and powerlifting programming for 2026: 10-20 hard sets per muscle weekly, train each twice, load 30-85% near failure, periodize.
Zone 2 Training: What the Literature Says
Zone 2 training is work below LT1 (~65-75% HRmax), the easy base of Seiler 80/20. What the literature shows on dose-response, how to find it, and the limits.
Morton 2018 Protein: 1.6 g/kg, 2.2 Upper 95% CI
Morton 2018 placed the protein plateau at 1.6 g/kg with a 95% CI upper bound near 2.2 g/kg (49 studies, n=1,863). Cutting raises it to 2.3-3.1 g/kg lean.
In under a minute.
Browse all 57 calculators.
FFMI, DOTS, 1RM, VO2 max, Zone 2, race times, recovery — every formula sourced.
FFMI
Calculate Fat-Free Mass Index to gauge muscularity and compare against natural benchmarks.
Open →1RM
Estimate one-rep max with Epley, Brzycki, and Lombardi formulas.
Open →Race Predictor
Race Time predictor: predict finish times across 5K, 10K, half marathon, and marathon from any known race result using Riegel's formula.
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