📊 portion size calculator — science-based tool that adapts dietary servings to your unique body, activity, and goals.
Used worldwide (USDA / WHO aligned), it translates daily calories into practical portions of vegetables, fruits, grains, protein, and dairy.
Accurate, inclusive, and mobile-friendly.
🍽️ Portion Size Calculator
global dietary standards · personalized servings
⚙️ Your profile
💡 Factor insights (US & Global): Age reduces BMR, gender affects basal metabolism, activity multiplies energy needs. The calculator uses Mifflin-St Jeor (accurate for most populations) and adjusts portions based on 2020-2025 US Dietary Guidelines, while being adaptable worldwide.
🌍 International inclusivity: Though baseline follows MyPlate (USA), portions are universally applicable. Many countries (UK, Australia, India, Japan) use similar energy-based recommendations; we provide contextual serving sizes (grams/cups) that fit any dietary culture.
📈 Your daily energy & portion map
⚡ BMR: — kcal/day
🎯 Calorie target: — kcal/day
🏆 Goal modifier: Maintenance
🍱 Recommended daily portions (based on your calorie target):
✔️ 1 veg serving = 1 cup raw leafy / ½ cup cooked | 1 fruit = medium apple | 1 grain = 1 slice bread or ½ cup rice | 1 protein = 1 oz meat/egg/tofu | 1 dairy = 1 cup milk/yogurt
📊 Portion distribution (servings/day)
Interactive graph updates with each change — visual portion guide
📌 Detailed factors affecting portion sizes (USA & Global reference)
Age: Older adults need fewer calories / slightly lower portions but higher nutrient density (USDA 2025)
Gender: Men typically have higher BMR → +10-15% portion volume vs women
Weight/Height: Directly impacts BMR; larger body → larger portion needs
Activity: Very active individuals need +500–800 kcal extra: grains/protein portions increase substantially
Goal (loss/gain): Weight loss uses ~500 kcal deficit → portions reduced moderately, muscle gain adds protein + complex carbs
🇺🇸 According to official US standards: For a moderately active adult (2000 kcal baseline) recommended portions: Vegetables 4 servings, Fruits 2, Grains 6, Protein 5.5oz eq, Dairy 3 cups. This calculator scales these scientifically to your personal calorie level, plus extra protein for muscle building and adjusted density for weight loss — following WHO & global norms.
🌎 How portion standards adapt across the world
While this tool uses energy-based scaling (universal), different countries express portions differently: Japan uses “servings per day” (1 SV = 40g carbs), India (ICMR) emphasizes grain & legume exchanges, European Nutri-Score aligns with similar calorie thresholds. Our calculator output (servings) can be converted locally: 1 grain serving ≈ 30g uncooked rice (global average). Use the results as a flexible guideline worldwide.