Food Portion Size Calculator

Portion Size Guide

Standard UK Portion Sizes

NHS / BNF guidelines for adult main course portions: pasta (dry) 75–100g per person; rice (dry) 60–75g; potato (raw) 150–200g; chicken breast 120–150g; red meat 100–150g; fish fillet 120–150g; soup 300–400ml as main. These are for a normal appetite — athletes, manual workers, or those in calorie surplus may need 20–30% more. The NHS Eatwell Guide recommends one-third of the plate as starchy carbohydrates, one-third vegetables, and one-third protein.

Dry vs Cooked Weight

Pasta and rice absorb water significantly during cooking: 75g dry pasta becomes approximately 200g cooked. 60g dry rice becomes approximately 180g cooked. Meat loses moisture during cooking: 150g raw chicken breast becomes approximately 110g cooked. Always weigh dry/raw if tracking nutritional intake precisely — calorie information on packaging refers to the dry or raw weight unless specifically labelled as cooked. Cooking methods affect final weight: boiling retains less weight than baking.

Scaling for Groups

For dinner parties and events: allow 10–20% extra for hungry eaters and second helpings — running out of food is more embarrassing than having leftovers. For pasta and rice, cooked leftovers refrigerate well for 2–3 days and reduce waste. For proteins, it is better to slightly under-cater on expensive items (steak, fish) and ensure generous carbohydrate and vegetable portions, as these are the most economical overflow options.

Reducing Food Waste

UK households waste approximately £700 worth of food per year on average. Better portion sizing is the most direct reduction. Strategies: weigh ingredients before cooking rather than estimating (3 weeks of weighing builds intuition). Plan meals and cook to recipe rather than guessing. Batch cook when ingredients are near their use-by date. WRAP (Waste and Resources Action Programme) estimates UK households throw away 4.5 million tonnes of edible food annually — approximately 20% of all food purc