Fitness Calculators
Free, verified fitness calculators with step-by-step guides and reference data.
Swing Weight Calculator — Bat MOI & Racquet Estimate
Estimate baseball/softball bat swing weight and drop from weight and balance point, plus a tennis racquet swingweight range classifier.
Navy Body Fat Calculator — Circumference Method
Estimate body fat using the US Navy circumference method (neck, waist, height, plus hip for women). Instant %BF with fitness category.
Weight Loss Percentage Calculator — % Lost & Goal Tracker
Find your weight loss percentage, track progress toward a goal weight, and see pounds remaining, plus a healthy pace check using the 0.5-1%/week guideline.
Batting Average Calculator — AVG, OBP, SLG & OPS
Calculate batting average from at-bats and hits, plus OBP, slugging percentage, and OPS from a full stat line. Correct no-leading-zero display.
Activity Calorie Calculator — Walking, Running, Cycling
Estimate calories burned walking, running, cycling, or on the treadmill using MET values from the Compendium of Physical Activities. Enter weight and duration.
Army Body Fat Calculator — 2024 One-Site Tape Test
Estimate Army body fat using the official 2024 one-site tape method or the legacy 3-site formula. Checks against age-based standards.
ERA Calculator — Earned Run Average & WHIP
Calculate ERA from innings pitched and earned runs, with correct baseball innings notation (outs, not decimals). Includes bonus WHIP calculation.
FFMI Calculator — Fat-Free Mass Index & Natural Limit
Calculate FFMI and normalized FFMI from weight, height, and body fat %. See where you fall vs the ~25 natural genetic limit from the Kouri et al. study.
DOTS Powerlifting Calculator: Score Your Squat, Bench & Deadlift
Calculate DOTS and Wilks scores from your powerlifting total. Bodyweight-adjusted for fair comparison across all weight classes and sexes.
RPE Calculator — Estimate 1RM & Find Training Weights
Calculate estimated 1RM from RPE, find target weights for any rep/RPE combo, and plan backoff sets using the Tuchscherer RTS chart.
Rucking Calorie Calculator: Calories Burned by Weight & Pace
Calculate rucking calories burned using the Pandolf equation. Enter body weight, pack weight, speed, grade, and terrain for precise results.
Warmup Sets Calculator: Barbell Warmup & Plate Loading Guide
Calculate barbell warmup sets by percentage for any working weight. Three protocols: Standard, Starting Strength, and Competition. Plate loading included.