How is one-rep max calculated?

One-rep max (1RM) is estimated using the Epley formula: 1RM = weight × (1 + reps/30). This works best for rep ranges of 2–10. For higher rep ranges, accuracy decreases. The calculator provides an estimate — your true 1RM may vary based on fatigue, technique, and other factors.

What are heart rate training zones?

Heart rate zones divide your effort into intensity levels based on percentage of maximum heart rate. Zone 1 (50–60%) is recovery, Zone 2 (60–70%) is aerobic base, Zone 3 (70–80%) is tempo, Zone 4 (80–90%) is threshold, and Zone 5 (90–100%) is maximal effort. Each zone targets different energy systems.

Why is VO2 max important?

VO2 max is the maximum rate at which your body can consume oxygen during exercise. It is considered the gold standard measure of cardiovascular fitness and is one of the strongest predictors of all-cause mortality. Improving VO2 max through regular exercise significantly reduces cardiovascular disease risk.

Fitness & Exercise Calculators

Calculate your one-rep max, target heart rate zones, and VO2 max estimate. Evidence-based tools for training programming, cardiovascular fitness assessment, and safe exercise prescription.

This category currently includes 10 tools, including Calories Burned Calculator, Sleep Calculator, and 1RM Calculator.

These resources are built for patients, coaches, and clinicians tracking health metrics over time. Use the results as decision support and pair them with full clinical context and local guidelines.

All Fitness Tools (10)

Calories Burned Calculator

Estimate calories burned from exercise using activity MET values, body weight, and duration. Useful for fitness planning and weight-management tracking. Combine with [TDEE Calculator](/tools/tdee-calculator) for full energy balance.

Sleep Calculator

Estimate ideal bedtimes or wake times based on 90-minute sleep cycles and sleep latency. Helps plan schedules around 7-9 hours of sleep. Poor sleep affects calorie balance — track with [TDEE Calculator](/tools/tdee-calculator).

1RM Calculator

Calculate your estimated one-rep max using Epley, Brzycki, and Lander formulas. Determine your maximum strength from submaximal lifts. Pair with [Heart Rate Zones Calculator](/tools/heart-rate-zones) and [VO2 Max Estimator](/tools/vo2-max-calculator) for complete fitness profiling.

Heart Rate Zones

Calculate your personal heart rate training zones using the Karvonen method. Optimize your cardio training with zones based on age and resting heart rate. Estimate aerobic capacity with [VO2 Max Estimator](/tools/vo2-max-calculator).

VO2 Max Estimator

Estimate your VO2 max from resting heart rate using the Uth method. Assess your cardiorespiratory fitness level and aerobic capacity. Higher VO2 max correlates with lower cardiovascular risk — see [ASCVD Risk Calculator](/tools/ascvd-risk).

Steps to Miles

Convert your daily step count to miles and kilometers using stride length estimated from your height and sex.

Running Pace Calculator

Predict your race times across 5K, 10K, half marathon, and marathon distances from a recent result, using the Riegel formula.

Metabolic Age Calculator

Estimate your metabolic age by comparing your resting metabolic rate per kilogram of body weight to typical age-related decline patterns.

Life Expectancy Calculator

Estimate life expectancy from a US population baseline (CDC, 2024) adjusted for smoking, exercise, BMI, alcohol use, and social connection.

Biological Age Calculator

Estimate whether your lifestyle suggests you're aging faster or slower than your chronological age, based on smoking, exercise, sleep, diet, stress, and resting heart rate.

Frequently Asked Questions

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