Nutrition Calculators

Alcohol Calorie Calculator

Calculate the calories from alcohol in a drink based on its volume and alcohol by volume (ABV) percentage.

BMI Calculator

Calculate Body Mass Index (BMI) from weight and height and see your WHO weight category classification.

BMR Calculator

Calculate your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation from weight, height, age, and sex.

Caffeine Safe Limit Calculator

Calculate a general safe daily caffeine limit based on body weight and the FDA's 400mg adult guideline, then compare it to your current intake.

Calorie Deficit Calculator

Calculate a daily calorie target for weight loss from your TDEE and a chosen weekly weight loss rate, with a minimum-intake safety check.

Calories From Macros Calculator

Calculate total calories from protein, carbohydrate, and fat grams using the standard Atwater energy factors used on nutrition labels.

Daily Calorie Needs Calculator

Calculate total daily energy expenditure using the Mifflin-St Jeor equation, combining your BMR with an activity multiplier for your actual calorie needs.

Fiber Intake Calculator

Look up your recommended daily fiber intake by age and gender from Institute of Medicine tables, plus an alternative calorie-based estimate.

Glycemic Load Calculator

Calculate glycemic load from a food's glycemic index and carbohydrate content per serving, with Low, Medium, and High classification.

Ideal Body Weight Calculator

Calculate estimated ideal body weight from height and sex using the Devine formula, commonly used as a medical reference point.

Macronutrient Ratio Calculator

Convert between calorie totals with percentage splits and protein, carb, and fat grams, or check the ratio behind grams you have already logged.

Meal Prep Portion Calculator

Divide a cooked batch into equal servings, or split a daily calorie and macro target evenly across a chosen number of meals per day.

Micronutrient Tracker Calculator

Compare your current intake of seven key vitamins and minerals against age- and gender-specific RDA targets, with a percentage and status label.

Net Carbs Calculator

Calculate net carbohydrates from total carbs, fiber, and sugar alcohols, the common tracking method used in low-carb and ketogenic diets.

Protein Intake Calculator

Calculate a daily protein range in grams from your body weight and activity level, using per-kilogram factors that scale with training intensity.

Sodium Intake Calculator

Calculate what percentage of the recommended 2300mg daily sodium limit your current intake represents.

Sugar Intake Limit Calculator

Calculate your recommended daily added sugar limit based on the WHO guideline of 10% of total calories, and see how your current intake compares.

Vitamin Dosage Calculator

Look up the Recommended Dietary Allowance for nine vitamins by age and gender, based on NIH Office of Dietary Supplements reference tables.

Waist to Hip Ratio Calculator

Calculate waist-to-hip ratio (WHR) from waist and hip measurements and see WHO reference ranges for health risk category.

Water Intake Calculator

Calculate daily water intake from body weight, with additions for exercise minutes and a hot climate layered onto a per-kilogram baseline.

Eating by the Numbers, Not Just by Feel

Nutrition needs vary by goal, not just by person — the same body needs a different macronutrient split for muscle gain, weight loss, or general maintenance. These ten calculators cover calorie, macro, and micronutrient math.

Disclaimer: These calculators are for informational and educational purposes only and do not constitute medical or dietary advice. Consult a registered dietitian or healthcare provider before making significant dietary changes.

Macronutrient Splits Vary by Goal

Illustrative macronutrient percentage splits by common approach
ApproachProteinCarbohydrateFat
Balanced / General Maintenance30%40%30%
Higher-Protein / Strength Focus40%30%30%
Lower-Carbohydrate30%20%50%

None of these is universally "correct" — the right split depends on activity level, goals, and individual response, which is why the Macronutrient Ratio Calculator works from your own target rather than a single fixed recommendation.

Popular Nutrition Calculators

  • Daily Calorie Needs Calculator — estimates maintenance calories from body stats and activity level.
  • Protein Intake Calculator — estimates daily protein target based on body weight and activity goals.
  • Glycemic Load Calculator — estimates a meal's effect on blood sugar from carbohydrate content and glycemic index.

Related: Health Calculators, Fitness Calculators for training-specific needs.