Estimates from general formulas, not medical advice. Check with a doctor before big changes to diet or training.
Convert steps to distance and calories. Without a measured stride, it is estimated from height: about 41% of height for walking, so a 175 cm (5 ft 9 in) man takes a 73 cm step and 10,000 steps cover about 7.3 km or 4.5 miles. At 70 kg that walk burns roughly 370 kcal and takes about 1.5 hours.
How to use
- Pick a calculator in the tabs and choose metric or imperial units; the choice is remembered.
- Body fat: measure your neck below the larynx, your waist at the navel (men) or narrowest point (women) and hips at the widest point, then enter them. Or switch to From BMI.
- Ideal weight: enter height and sex. One-rep max: enter the weight and reps of a hard set. Calories: pick an activity and minutes. Water: weight and daily exercise. Steps: step count and your height or stride.
- Results update as you type. Tap any result to copy it.
- The US Navy method (Hodgdon and Beckett, 1984) is usually within 3–4 percentage points of a DEXA scan. The BMI method (Deurenberg, 1991) is rougher and overestimates fat in muscular people.
- Ideal weight formulas were made for drug dosing, not as health targets; the BMI range is a broader guide.
- 1RM: Epley = w × (1 + reps/30), Brzycki = w × 36 / (37 − reps), Lombardi = w × reps^0.10. All are most accurate for 2 to 10 reps.
- Calories use MET × weight (kg) × hours from the Compendium of Physical Activities and include your resting burn. Fitness trackers and machines may show different numbers.
- Water: about 35 ml per kg plus exercise. Food covers roughly 20% of water intake; EFSA suggests about 2.0 L a day for women and 2.5 L for men from all sources.
How the target is worked out
The base is about 35 ml per kg of body weight, then 12 ml is added for each minute of exercise and 500 ml for hot weather. A 70 kg person who exercises 30 minutes a day gets 2,450 + 360 = about 2.8 liters (95 fl oz), or 11 glasses of 250 ml.
This total covers all drinks. Food usually supplies around 20% of daily water, and the European Food Safety Authority (EFSA) suggests about 2.0 liters a day for women and 2.5 liters for men from all sources.
Listen to your body
Thirst and pale yellow urine are good everyday guides. Needs rise with heat, altitude, illness, pregnancy and breastfeeding. Drinking far more than you need does not help and, in extreme cases, can be dangerous. People with heart or kidney conditions should follow their doctor’s advice on fluids.
These are estimates from general formulas, not medical advice. Nothing you enter leaves your device.
Frequently asked questions
How much water should I drink a day?
A common guide is about 35 ml per kg of body weight, plus more for exercise and heat. For 70 kg that is around 2.5 liters before exercise.
Do coffee and tea count toward water intake?
Yes. Moderate amounts of coffee and tea hydrate almost as well as water. Food such as fruit, vegetables and soup also adds water.
How much extra water do I need when exercising?
This calculator adds 12 ml per minute, about 0.7 liters an hour. Long or hot sessions may need more, ideally with electrolytes.
Is 8 glasses a day right?
Eight glasses of 250 ml is 2 liters, close to EFSA’s guide for women. Larger or more active people usually need more.
Can you drink too much water?
Yes. Drinking very large amounts in a short time can lower blood sodium. Spread drinks through the day and follow thirst.