Sleep Calculator

A sleep cycle is a pattern of sleep stages that repeats throughout the night. Each cycle lasts about 90 minutes and includes light sleep, deep sleep, and REM (rapid eye movement) sleep. We typically go through 4-6 cycles per night. Waking up at the end of a cycle (rather than in the middle) helps you feel more awake and refreshed.

Most adults need 7-9 hours of sleep per night (roughly 5-6 full cycles). Teenagers need 8-10 hours, and children need even more. However, quality matters too —6 hours of uninterrupted sleep with complete cycles can feel better than 8 hours of fragmented sleep.

Sleep researchers estimate that the average person takes about 10-15 minutes to fall asleep after getting into bed. We use 14 minutes as a standard estimate. If you know it takes you longer or shorter to fall asleep, adjust accordingly.

No. This sleep calculator is for informational purposes only and is not a substitute for professional medical advice. If you have persistent sleep issues, insomnia, or other health concerns, please consult a healthcare professional or sleep specialist.

A BMI between 18.5 and 24.9 is considered normal weight. Below 18.5 is underweight, 25-29.9 is overweight, and 30 or above is obese. However, BMI does not account for muscle mass, bone density, age, and other factors, so it should be used as a general guideline rather than a definitive measure.

Daily calorie needs depend on age, gender, weight, height, activity level, and goals. An average sedentary adult needs about 1800-2200 calories for women and 2200-2600 for men. To lose weight, aim for a moderate deficit of 300-500 calories below maintenance.

BMI is less accurate for athletes and bodybuilders because muscle is denser than fat. A muscular person with low body fat can have a BMI in the overweight or obese range. For athletes, body fat percentage, waist circumference, and overall fitness level are better health indicators.

BMR (Basal Metabolic Rate) is the number of calories you burn at rest. The Mifflin-St Jeor equation is the most accurate: for men BMR = 10*weight(kg) + 6.25*height(cm) - 5*age + 5, for women BMR = 10*weight(kg) + 6.25*height(cm) - 5*age - 161.

Safe weight loss is 0.5-1 kg (1-2 lbs) per week through a combination of moderate calorie deficit, balanced nutrition, and regular physical activity. Extreme diets can cause muscle loss, nutrient deficiencies, and rebound weight gain. Consult a healthcare provider before starting any weight loss plan.

A kilogram of muscle weighs the same as a kilogram of fat, but muscle is much denser and takes up less volume. This is why two people of the same height and weight can look very different depending on their body composition. Strength training can change your body shape without changing the scale number.

TDEE (Total Daily Energy Expenditure) is the total number of calories you burn in a day, including BMR plus activity from exercise, movement, and digestion. It is calculated by multiplying your BMR by an activity factor (1.2 for sedentary, up to 1.9 for very active).

Poor sleep disrupts hunger hormones (ghrelin and leptin), increases cravings for high-calorie foods, lowers metabolism, and reduces motivation to exercise. Getting 7-9 hours of quality sleep is an important factor in maintaining a healthy weight and overall health.

A BMI between 18.5 and 24.9 is considered normal weight. Below 18.5 is underweight, 25-29.9 is overweight, and 30 or above is obese. However, BMI does not account for muscle mass, bone density, age, and other factors, so it should be used as a general guideline rather than a definitive measure.

Daily calorie needs depend on age, gender, weight, height, activity level, and goals. An average sedentary adult needs about 1800-2200 calories for women and 2200-2600 for men. To lose weight, aim for a moderate deficit of 300-500 calories below maintenance.

BMI is less accurate for athletes and bodybuilders because muscle is denser than fat. A muscular person with low body fat can have a BMI in the overweight or obese range. For athletes, body fat percentage, waist circumference, and overall fitness level are better health indicators.

BMR (Basal Metabolic Rate) is the number of calories you burn at rest. The Mifflin-St Jeor equation is the most accurate: for men BMR = 10*weight(kg) + 6.25*height(cm) - 5*age + 5, for women BMR = 10*weight(kg) + 6.25*height(cm) - 5*age - 161.

Safe weight loss is 0.5-1 kg (1-2 lbs) per week through a combination of moderate calorie deficit, balanced nutrition, and regular physical activity. Extreme diets can cause muscle loss, nutrient deficiencies, and rebound weight gain. Consult a healthcare provider before starting any weight loss plan.

A kilogram of muscle weighs the same as a kilogram of fat, but muscle is much denser and takes up less volume. This is why two people of the same height and weight can look very different depending on their body composition. Strength training can change your body shape without changing the scale number.

TDEE (Total Daily Energy Expenditure) is the total number of calories you burn in a day, including BMR plus activity from exercise, movement, and digestion. It is calculated by multiplying your BMR by an activity factor (1.2 for sedentary, up to 1.9 for very active).

Poor sleep disrupts hunger hormones (ghrelin and leptin), increases cravings for high-calorie foods, lowers metabolism, and reduces motivation to exercise. Getting 7-9 hours of quality sleep is an important factor in maintaining a healthy weight and overall health.