Performance calculators
Deterministic fitness math for lifters and runners.
46 calculators for FFMI, DOTS, 1RM, VO2 max, Zone 2, race times, and recovery. Every formula sourced, every limit named.
Free · Private · No signup · 46 tools
Pick your goal
Optimize Body Composition
Dial in calorie targets for recomposition — preserve strength while dropping body fat.
Open →Build Strength & Muscle
Translate your calorie target into macro and protein plans optimized for strength gains.
Open →Benchmark Your Strength
See where your lifts rank with DOTS, strength standards, and 1RM projections.
Open →Plan Your Race
Predict race times, dial in training paces, and calibrate heart rate zones for distance running.
Open →Recover Better
Align sleep, hydration, and intensity to improve training quality.
Open →Understand Body Composition
Use simple body composition estimates to track direction over time.
Open →Worth reading.
Long-form articles
Evidence-backed, sourced, dated.
The 2026 Lifter's Guide to Evidence-Based Programming
Volume, intensity, frequency, and specificity reviewed through the Schoenfeld meta-analyses and the hypertrophy literature. With dated caveats.
Zone 2 Training: What the Literature Actually Says
Polarised training, Seiler's 80/20, Stöggl & Sperlich 2014, and the San Millán mitochondrial framing — separated from the social-media version.
Protein for Lifters: The 2026 Dose-Response Meta-Analyses
Morton 2018 BJSM, Helms 2014 JISSN, and the current ceiling around 1.6–2.2 g/kg — plus what the bodybuilder-contest literature adds.
In under a minute
Quick picks
A useful answer fast — pick one, get a number.
FFMI
Calculate Fat-Free Mass Index to gauge muscularity and compare against natural benchmarks.
Open →DOTS/Wilks
Compare powerlifting strength across weight classes with IPF DOTS and Wilks-2020 coefficients.
Open →1RM
Estimate one-rep max with Epley, Brzycki, and Lombardi formulas.
Open →Body Recomp
Plan body-fat reduction pace, deficit targets, and protein needs around a timeline.
Open →Race Predictor
Predict finish times across 5K, 10K, half marathon, and marathon from any known race result using Riegel's formula.
Open →Heart Rate Zones
Calculate personalized training zones with the Karvonen method.
Open →Strength Standards
Rank your lifts from Beginner to Elite based on bodyweight ratios.
Open →Running Pace
Calculate pace per km and mile and project race finish times from one run.
Open →All Tools 46
Nutrition
TDEE
Estimate your daily energy expenditure with Mifflin-St Jeor + activity factors.
Open →BMR
Estimate basal metabolic rate and maintenance calories using Mifflin-St Jeor assumptions.
Open →Macros
Convert calorie targets into protein, carbs, and fat grams for your goal.
Open →Protein Intake
Get daily protein targets based on training level and goal.
Open →Water Intake
Calculate daily water intake based on weight, activity level, and climate.
Open →Fasting Planner
Plan protocol-based eating and fasting windows with a 24-hour timeline and 5:2 day picker.
Open →Meal Macro Split
Convert daily macro targets into per-meal protein, carb, and fat execution numbers.
Open →Creatine Intake
Estimate creatine maintenance and loading doses from body weight and training frequency.
Open →Food to Exercise
See how long you need to exercise to burn off any food, personalized by bodyweight.
Open →Macro Cycling
Calculate different macros for training days and rest days with carb cycling for recomp, lean bulk, or cut goals.
Open →Strength
Progressive Overload
Project lifting progression with weekly overload and planned deload cycles.
Open →1RM
Estimate one-rep max with Epley, Brzycki, and Lombardi formulas.
Open →Strength Standards
Rank your lifts from Beginner to Elite based on bodyweight ratios.
Open →DOTS/Wilks
Compare powerlifting strength across weight classes with IPF DOTS and Wilks-2020 coefficients.
Open →Workout Volume
Calculate total training volume and compare against optimal ranges per muscle group.
Open →Plate Loader
Calculate which weight plates to load on each side of a barbell to hit your target weight in kg or lbs.
Open →DOTS/Wilks/GL
Compare DOTS, Wilks, and Goodlift scores side by side to see which system rates your powerlifting total highest.
Open →RPE Converter
Convert RPE and reps to percentage of 1RM with a full interactive RPE chart based on the Tuchscherer table.
Open →Strength Percentile
Find out where your squat, bench, deadlift, or OHP ranks against other lifters by bodyweight and sex.
Open →Meet Attempts
Plan powerlifting meet attempts with opener, second, and third attempt suggestions based on 1RM and confidence.
Open →Cardio
Running Pace
Calculate pace per km and mile and project race finish times from one run.
Open →VO₂ Max
Estimate aerobic capacity with Cooper run, Rockport walk, or no-exercise questionnaire methods.
Open →Walking Calories
Estimate calories burned from walking using speed, duration, body weight, and incline.
Open →Calories Burned
Estimate exercise calorie burn from body weight, duration, MET intensity, and incline.
Open →RHR
Assess cardiovascular fitness from your resting heart rate — classification, cardio age, and improvement targets.
Open →Swim Pace
Calculate swim pace, total time, or distance with SWOLF and effort-zone context.
Open →Run Training Paces
Get personalized Easy, Tempo, Threshold, Interval, and Speed training paces from a recent race time using the Daniels VDOT method.
Open →Race Predictor
Predict finish times across 5K, 10K, half marathon, and marathon from any known race result using Riegel's formula.
Open →FTP Zones
Calculate your 7 Coggan power training zones from FTP or a 20-minute test result with W/kg ratio.
Open →Treadmill Pace
Convert treadmill speed to running pace with incline-adjusted flat equivalent, projected race times, and calorie estimates.
Open →Zone 2 HR
Calculate your Zone 2 heart rate with Maffetone, Karvonen, % Max HR, and lactate threshold methods compared side by side.
Open →Body Composition
BMI
Calculate BMI quickly with a plain-language range explanation and limitations.
Open →Body Fat %
Estimate body fat percentage using the U.S. Navy circumference method.
Open →Ideal Weight
Compare Devine, Robinson, Miller, and Hamwi formulas as a realistic range.
Open →Waist-to-Hip Ratio
Calculate waist-to-hip ratio and assess body composition using WHO guidelines.
Open →FFMI
Calculate Fat-Free Mass Index to gauge muscularity and compare against natural benchmarks.
Open →LBM
Estimate lean body mass using Boer, James, Hume, and Peters formulas from height and weight.
Open →Flex Score
Estimate your flexibility percentile and rating from a sit-and-reach test score, adjusted for age and sex.
Open →Muscle Potential
Estimate your natural muscular potential with the Casey Butt model and see how close you are to your genetic limit.
Open →Recovery
Heart Rate Zones
Calculate personalized training zones with the Karvonen method.
Open →Sleep
Calculate optimal bed and wake times based on 90-minute sleep cycles.
Open →Sweat Rate
Calculate your personal sweat rate from pre/post-exercise weigh-ins and estimate fluid and sodium losses using ACSM guidelines.
Open →Sleep Debt
Track 7 nights of sleep to calculate accumulated sleep debt with a recovery timeline and quality assessment.
Open →Planning
Calorie Deficit
Estimate required daily calorie deficit for a target timeline and bodyweight change.
Open →Body Recomp
Plan body-fat reduction pace, deficit targets, and protein needs around a timeline.
Open →Hybrid Planner
Build a weekly schedule that balances running and lifting with interference warnings and recovery guidance.
Open →