How Much Protein Do You Actually Need Per Day?

The RDA is a floor, not a target

The Recommended Dietary Allowance for protein is 0.8 grams per kilogram of body weight per day. That figure comes from the Institute of Medicine's Dietary Reference Intakes, and it is the number behind almost every "you need X grams" claim you will read. What is usually left out is what it was designed to represent: the intake that meets the needs of nearly all healthy, sedentary adults - in other words, a minimum that keeps the body in nitrogen balance, not an optimum for anyone with a training schedule.

For a 70 kg (154 lb) adult the RDA works out at about 56 g of protein a day. For a 90 kg (198 lb) adult it is about 72 g. Those totals are easier to hit than most people assume: a 3 oz chicken breast and a container of Greek yogurt come to about 44 g between them, roughly three-quarters of the first one.

The 50 g figure you see on nutrition labels is a different thing again. That is the FDA's Daily Value, a single reference number used to calculate the "% Daily Value" column on packaging so that every product can be compared on the same scale. It is not personalised, and ProteinTally uses it only for the %DV line on each food page - never as a recommendation.

• RDA: 0.8 g per kg of body weight per day - the sedentary-adult minimum.
• Daily Value: a flat 50 g label reference used for %DV comparisons on packaging.
• Neither is a personalised target; both are reference points.

Why grams per kilogram beats a flat number

Protein is not stored the way fat and carbohydrate are. The body maintains a working pool of amino acids that is constantly being drawn down to repair and replace tissue, and daily intake is what refills it. How much repair work there is to do depends mostly on how much lean tissue you carry, which is why the requirement is expressed per kilogram of body weight instead of as one number for everybody.

The practical consequence is that a 55 kg person and a 100 kg person following the same "100 g of protein a day" advice are following two completely different recommendations. For the first that is 1.8 g/kg - a figure normally reserved for someone training hard. For the second it is 1.0 g/kg, barely above the sedentary floor. Same number on the plate, opposite meaning.

If you think in pounds, the conversion is simple: divide your weight in pounds by 2.2 to get kilograms, then multiply by the g/kg figure you are aiming at. A 165 lb person is 75 kg, so the RDA is about 60 g and a 1.6 g/kg target is about 120 g.

The higher ranges, and who they are for

Once regular training enters the picture, the published ranges move well above the RDA. Position statements from the International Society of Sports Nutrition and guidance from the American College of Sports Medicine and the Academy of Nutrition and Dietetics put the useful band for active people at roughly 1.2-2.0 g/kg per day. The reasoning is that training increases both the rate at which muscle protein is broken down and the rate at which it can be rebuilt, and the raw material for the rebuilding comes from the diet.

Within that band, the specific target depends on what the training is for. Endurance athletes sit toward the lower end, around 1.2-1.4 g/kg, because their demand is largely repair and recovery. Strength training sits higher, around 1.6-2.0 g/kg. Someone deliberately trying to add muscle is usually given 1.6-2.2 g/kg, and someone eating in a calorie deficit is often given the highest figures of all - up to about 2.4 g/kg - because protein needs rise, not fall, when total energy intake drops.

Two honest caveats. First, these are ranges rather than thresholds; the difference between 1.7 and 1.9 g/kg is not something you would ever notice, whereas the difference between 0.8 and 1.6 might be. Second, more is not indefinitely better. Intakes above roughly 2 g/kg have not been shown to add anything for most people, and past a point the extra protein is simply used for energy like any other calorie.

• Sedentary: 0.8-1.0 g/kg - the RDA and just above it.
• Generally active: 1.2-1.6 g/kg.
• Endurance training: 1.2-1.4 g/kg.
• Strength training: 1.6-2.0 g/kg.
• Building muscle: 1.6-2.2 g/kg. Eating at a deficit: 1.6-2.4 g/kg.

Turning a g/kg target into food

A number in grams per kilogram only becomes useful once you know what it looks like on a plate. Take a 75 kg person training with weights, aiming at the middle of the 1.6-2.0 g/kg band - about 135 g a day. Split across three meals and a snack that is roughly 35 g per meal, which is one ordinary portion of a main protein source plus whatever the rest of the plate contributes.

The examples below are all single, unexceptional servings. Notice that a 35 g meal target does not require a single 35 g food: 3 oz of salmon plus a cup of cooked lentils is nearly 37 g between them, and neither portion is unusual.

This is also where an honest look at your current intake helps more than any calculation. Most people who think they are short on protein are short at breakfast and at snacks, not at dinner - the evening meal is usually already built around a protein source, while the morning and mid-afternoon are built around grains and fruit. Logging two ordinary days in the tracker tends to make the pattern obvious immediately.

Where the numbers stop being general

Everything above describes healthy adults. Several situations shift the picture enough that a general guideline stops being the right tool, and they are worth naming explicitly rather than burying.

Older adults are frequently given intakes above the RDA in the research literature, on the grounds that the body's response to a given dose of protein appears to blunt with age. Pregnancy and breastfeeding raise requirements. Reduced kidney function, liver disease, and some metabolic conditions can make a higher intake inappropriate, and in those cases the target is a clinical decision rather than a calculator output. Children and adolescents have their own age-banded reference values that do not map onto adult g/kg figures.

If any of those apply to you, treat the ranges in this guide as context for a conversation with a doctor or registered dietitian, not as a plan. ProteinTally is a reference tool; it does not know anything about your medical history and cannot account for it.

A sensible way to use the numbers

The most common mistake is precision theatre - agonising over whether the target should be 1.7 or 1.8 g/kg while having no idea what the current intake actually is. Order of operations matters here: measure first, then adjust.

Work out your range with the protein calculator, then log a few typical days without changing anything. If your usual intake already lands inside the range, there is nothing to fix. If it is well below, the gap is almost always closable with one addition per day rather than a diet overhaul - a yogurt at breakfast, a handful of edamame, a can of tuna at lunch.

And keep the ranking distinction in mind when you pick what to add. A food can be high in protein per serving without being protein-dense per calorie, and which of those two you want depends on whether you are trying to hit a total or trying to hit it without adding much energy. That trade-off has its own guide.

• Calculate the range, don't guess it.
• Log two or three ordinary days before changing anything.
• Close gaps with one repeatable addition, not a new diet.
• Aim at the range, not at a decimal point inside it.