BMI, BMR, daily calories, macros — instant & free
Body Mass Index helps assess if your weight is in a healthy range for your height.
Enter your weight and height to calculate BMI
Calculate your Basal Metabolic Rate and daily calorie needs based on activity level.
BMR
—
calories/day at rest
Maintenance Calories
—
to maintain weight
Weight Loss
—
-15% deficit
Weight Gain
—
+15% surplus
Calculate your daily macronutrient needs (carbs, protein, fat).
Carbohydrates
—
grams/day
Protein
—
grams/day
Fat
—
grams/day
Body Mass Index (BMI) is a simple calculation using height and weight to estimate body fat. It's calculated as weight (kg) divided by height squared (m²). While widely used, BMI doesn't account for muscle mass, bone density, or body composition, so it should be one of several health indicators.
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to maintain vital functions like breathing and circulation. We use the Mifflin-St Jeor equation, considered the most accurate for estimating BMR. Your total daily energy expenditure (TDEE) is BMR multiplied by your activity level.
Weight loss occurs when you consume fewer calories than your body burns (calorie deficit). A 15% deficit is generally sustainable for most people. One pound of fat equals approximately 3,500 calories, so a daily 500-calorie deficit could lead to about 1 pound of weight loss per week. Extreme deficits aren't recommended without medical supervision.
Macronutrients (carbs, protein, fat) affect satiety, energy, and body composition differently. Protein helps preserve muscle during weight loss and increases satiety. Carbs provide quick energy, while fats support hormone production and nutrient absorption. The optimal ratio varies by individual, but balanced intake typically works best for sustainable weight management.
These calculators provide general estimates and are NOT suitable as standalone tools for: pregnant or breastfeeding individuals, people with eating disorders, those with metabolic conditions (diabetes, thyroid issues), athletes with high muscle mass, individuals under 18, or anyone with medical conditions affecting metabolism. Always consult healthcare professionals for personalized nutrition advice.
Yes, all calculators on DietDelta are 100% free with no signup required. All calculations run in your browser, and we don't collect or store any personal information.
No. DietDelta provides educational tools only and does not replace medical or nutritional advice. Always consult qualified healthcare professionals for personalized health guidance.
Our calculators can help you understand your calorie needs and create awareness, but sustainable weight loss should be guided by healthcare professionals. Use these tools as starting points, not medical prescriptions.
We use the scientifically-validated Mifflin-St Jeor equation for BMR calculations. However, individual variations exist due to genetics, muscle mass, and metabolic factors. Use results as general guidelines and adjust based on real-world results.
No. All calculations happen entirely in your browser. We don't store, collect, or transmit any personal information. Your privacy is completely protected.
Yes, you can use DietDelta as often as needed to track your health metrics and plan your nutrition. Many people bookmark the site and return regularly to recalculate as their weight or activity levels change.
DietDelta is built with privacy, accuracy, and education in mind. We use scientifically-validated formulas, provide clear explanations, require no signup, store no data, and present information in a calm, trustworthy manner without aggressive marketing.
No. DietDelta focuses on providing calculation tools and educational content. Personalized meal plans should be created with registered dietitians or nutritionists who can account for your specific health conditions, preferences, and goals.
DietDelta provides educational tools only and does not replace medical or nutritional advice. These calculators offer general estimates based on widely-used formulas. Individual results vary significantly due to genetics, medical conditions, medications, and other factors.
Always consult qualified healthcare professionals (doctors, registered dietitians, nutritionists) before making significant changes to your diet or exercise routine, especially if you have medical conditions, take medications, are pregnant, or have a history of eating disorders.