Free Fitness Calculators Online

1. Calculate BMI to understand current status
2. Find TDEE with Calorie Calculator
3. Set target at TDEE minus 500 calories
4. Use Macro Calculator for protein/carb/fat split
5. Set daily water intake goal

1. Test your current lifts for key exercises
2. Open 1RM Calculator
3. Enter weight lifted and reps
4. Get your estimated one rep max
5. Use training percentages for program design

1. Open Heart Rate Zone Calculator
2. Enter your age and resting heart rate
3. Get all 5 training zones
4. Zone 2 for fat burning and endurance
5. Zone 4-5 for VO2 max and performance

1. Open Body Fat Calculator
2. Measure waist at navel level
3. Measure neck below the larynx
4. Enter measurements with height
5. Track monthly to see trends

The World Health Organization classifies BMI as: Under 18.5 = Underweight, 18.5-24.9 = Normal weight, 25.0-29.9 = Overweight, 30.0 and above = Obese. However, BMI has limitations — it does not distinguish between muscle and fat, may misclassify muscular athletes as overweight, and may underestimate health risks in people with low muscle mass. Use it as one indicator alongside body fat percentage and waist circumference.

TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns per day, accounting for your activity level. To lose weight, consume 300-500 calories less than your TDEE per day — this creates a deficit that leads to approximately 0.3-0.5 kg of fat loss per week. Avoid cutting more than 700 calories below TDEE as this causes muscle loss and metabolic adaptation.

For general fitness: 0.8-1.0g protein per kg of bodyweight. For fat loss while preserving muscle: 1.6-2.2g/kg. For muscle building: 1.6-2.0g/kg. For athletes in heavy training: up to 2.5g/kg. A 75kg person targeting fat loss needs approximately 120-165g of protein per day. Our Macro Calculator sets protein based on your goal and body weight.

The Epley formula estimates your one rep max from a submaximal effort: 1RM = Weight × (1 + Reps/30). For example, if you bench press 80kg for 5 reps: 1RM = 80 × (1 + 5/30) = 80 × 1.167 = 93.3kg. The formula is most accurate for sets of 2-10 reps. For sets above 10 reps, accuracy decreases. Our 1RM Calculator also shows training percentages for strength (85-90%), hypertrophy (65-80%), and endurance (50-65%) ranges.

General recommendation is 33ml of water per kg of bodyweight per day. A 70kg person needs approximately 2.3 litres (about 9 glasses of 250ml). Add 500ml on days with moderate exercise and 750ml-1 litre on days with intense exercise. Hot weather and high-altitude environments also increase requirements. Coffee and tea count towards hydration despite being diuretics at moderate intake.