Protein Calculator

What are proteins?

Proteins are one of the three energy-providing macronutrients, with fats and carbohydrates, but energy is almost a side job: proteins do much of the actual work inside cells. They form the structure of tissues and organs, regulate them, and carry signals and molecules around the body. A protein is a chain of amino acids — 20 kinds in total, and their sequence decides the protein's shape and role. Nine of them are essential amino acids: the body cannot make them, so they must come from food, and missing them in sufficient amounts can be fatal. Foods supplying all nine in good amounts are complete protein sources — animal foods (meat, dairy, eggs, fish) and a few plant foods (soy, quinoa, buckwheat).

By the job they do, proteins fall into families: antibodies, which bind foreign particles such as viruses and bacteria; enzymes, which build new molecules and run the body's chemical reactions; messengers, which transmit signals that coordinate body processes; structural components, the building blocks that let the body move; and transport/storage proteins, which carry molecules where they are needed. With that much riding on them, keeping protein intake adequate is basic maintenance, not a bodybuilding niche.

How much protein do I need?

Daily need depends on energy intake, growth, and above all body weight and activity level. It is usually quoted per kilogram of body weight, as a share of calories (10-35%), or as a flat figure by age. The commonly cited RDA is 0.8 g/kg — a minimum for basic nutritional requirements, below which deficiency becomes a risk. The recommended working range is roughly 0.8 to 1.8 g/kg: the bottom suits sedentary adults, while highly active people and those building muscle sit at the top, with some sources suggesting 1.8 to 2 g/kg for the very active. It is not an exact science — a dietitian, doctor, or qualified trainer can pin down an individual target. The three figures this calculator shows are the ADA range for your activity level, the CDC's 10-35%-of-calories band, and the WHO safe lower limit of 0.83 g/kg.

Recommended dietary allowance (RDA) of protein, based on age

Extra protein requirements for pregnancy and lactation

Foods high in protein

Most people get the bulk of their protein from meat and dairy, and those are the easiest route to the RDA — but far from the only one. Plant-based sources usually carry less protein per serving, yet a varied mix of them covers the requirement comfortably, and a blend of meat, dairy, and plant foods is the balanced pattern. Complete proteins (all nine essential amino acids) include, from animal sources: eggs, chicken breast, cottage cheese, Greek yogurt, milk, lean beef, tuna, turkey breast, fish, and shrimp; and from plants: buckwheat, hummus with pita, soy products (tofu, tempeh, edamame), peanut butter on bread, beans with rice, quinoa, hemp and chia seeds, and spirulina. Incomplete proteins are not a problem food either — almonds, oats, broccoli, lentils, Ezekiel bread, chia and pumpkin seeds, peanuts, Brussels sprouts, grapefruit, green peas, avocados, and mushrooms are all healthy high-protein foods; variety across the day supplies the missing amino acids. Balance, as ever, is the point.

Amount of protein in common food