One-Rep Max (1RM) Calculator
The one-rep max calculator estimates the most weight you could lift for a single repetition of an exercise, from a set you can do for several reps. It’s the basis of most strength programs, which prescribe loads as a percentage of your 1RM.
- Formula used: Epley – 1RM = weight × (1 + 0.033 × reps).
- Use it for: Setting training loads, for example about 70–80% of 1RM for hypertrophy.
VO2 Max Calculator
VO2 max is the maximum amount of oxygen your body can use during intense exercise, a key measure of aerobic endurance. The higher your VO2 max, the better your cardiovascular fitness.
- Calculation method: the heart-rate ratio method (Uth–Sørensen): VO2 max ≈ 15.3 × maximum heart rate ÷ resting heart rate, with maximum heart rate estimated as 220 − age. A lab test or a field test such as the Cooper test is more accurate.
- Use it for: Tracking cardiovascular progress and planning endurance training.
Target Heart Rate Calculator
Finds the heart rate range for moderate to vigorous cardio training.
- Calculation method: the Karvonen method, 50–85% of your heart rate reserve (maximum heart rate minus resting heart rate), added to your resting heart rate.
- Use it for: Cardio intensity planning, so you’re neither undertraining nor overtraining.
Calories Burned Calculator (Based on Activity)
Estimates how many calories you burn from your weight, the type of activity and its duration, using MET (metabolic equivalent of task) values.
- Use it for: Planning workouts to support fat loss or energy balance.
TDEE Calculator (Total Daily Energy Expenditure)
TDEE is the total number of calories your body uses in a day: your basal metabolic rate (BMR) plus everything you burn through activity.
- Calculation method: BMR from the Harris–Benedict equation, multiplied by an activity factor from 1.2 (sedentary) to 1.9 (extra active). The calorie needs calculator uses the newer Mifflin–St Jeor equation.
- Use it for: Weight management, whether you’re cutting, bulking or maintaining.
Macronutrient Calculator
Splits your daily calories into grams of protein, carbohydrates and fat for your goal: weight loss (40/30/30), maintenance (30/30/40) or muscle gain (35/25/40, as protein/fat/carbs).
- Use it for: Building a meal plan that matches your training goal. For a custom split or keto macros, see the nutrition calculators.
Workout Recovery Time Calculator
Recovery is just as important as the workout itself. This calculator gives a rough estimate of how long to rest from your workout’s intensity, its duration and how many muscle groups you trained.
- Use it for: Avoiding overtraining. Sleep, nutrition and stress also affect recovery, so listen to your body.
Running Pace Calculator
Enter a distance and your time to get your pace per kilometre and per mile, your average speed, and predicted finish times for the 5K, 10K, half marathon and marathon.
- Calculation method: pace = time ÷ distance. Race predictions use Peter Riegel’s formula, T2 = T1 × (D2 ÷ D1)1.06.
- Use it for: Planning training runs and setting realistic race goals.
Heart Rate Zone Calculator
Training in the right heart rate zone makes each session count, from easy recovery runs (zone 1–2) to threshold and interval work (zone 4–5).
- Calculation method: maximum heart rate from the Tanaka formula (208 − 0.7 × age). With your resting heart rate, zones use your heart rate reserve (Karvonen method); without it, they are percentages of your maximum.
- Use it for: Setting targets on your watch or bike computer.
Steps to Calories Calculator
Turns a step count into distance, time and calories burned, based on your height, weight and walking or running pace.
- Calculation method: stride length is about 41–45% of your height when walking and 65% when running; calories use MET values (2.8 for a slow walk up to 9.8 for running) × body weight × time.
- Use it for: Understanding what your daily step goal means in energy and distance.
Why use fitness performance calculators?
- Personalized training: tailor your workouts to your own numbers.
- Better goal tracking: know where you stand and how to progress.
- Efficient planning: avoid plateaus and get more from every session.
- Injury prevention: make room for recovery and avoid burnout.