How Much Protein Do I Need a Day?

How This Calculator Works

Your target is your body weight in kilograms multiplied by a coefficient chosen for your activity level and goal. Three adjustments then refine it.

These targets are general fitness guidance, not medical or dietary advice. If you have kidney disease, liver disease, or another condition affecting protein metabolism, protein restriction may be part of your treatment — get your target from your doctor or a registered dietitian instead of a calculator.

Calculators for Specific Goals

Same engine, preset for your situation, with the research that applies to it.

Frequently Asked Questions

The questions people ask most about daily protein targets.

How much protein do I need a day?

For most adults, somewhere between 1.2 and 2.0 grams of protein per kilogram of body weight per day. The Recommended Dietary Allowance of 0.8 g/kg is the amount needed to prevent deficiency in sedentary adults, not the amount associated with the best outcomes for muscle, satiety, or body composition. A sedentary adult at 70 kg needs at least 56 g, while the same person doing resistance training is better served by around 112 g.

How do you calculate protein intake?

Multiply your body weight in kilograms by a coefficient that reflects your activity level and goal. Use roughly 1.2 g/kg for general health, 1.6 g/kg if you do resistance training, 1.8 to 2.0 g/kg when losing fat and trying to preserve muscle, and 1.0 to 1.2 g/kg if you are over 65. To convert from pounds, divide your weight by 2.2 first. If you carry significant excess body fat, calculate against a lower reference weight, because protein needs track lean mass rather than total mass.

How much protein do I need to build muscle?

Around 1.6 grams per kilogram of body weight per day, rising to about 2.2 g/kg for people training hard. A 2018 meta-analysis by Morton and colleagues found that gains in lean mass continued to improve as protein intake rose to roughly 1.6 g/kg, with little detectable additional benefit beyond that point. Protein alone does not build muscle — it has to be paired with resistance training and enough total calories.

How much protein should I eat to lose weight?

Higher than at maintenance, typically 1.8 to 2.4 grams per kilogram of body weight per day. Eating in a calorie deficit puts your body in a net catabolic state, and a higher protein intake helps preserve lean mass while you lose fat. Protein is also the most satiating macronutrient per calorie and has the highest thermic effect, both of which make a deficit easier to sustain.

Is 0.8 grams of protein per kilogram enough?

It is enough to prevent deficiency, but it is a floor rather than a target. The RDA was derived from nitrogen balance studies to establish the intake that meets the needs of almost all healthy sedentary adults. It was never intended to describe the intake that optimises muscle mass, appetite control, or preservation of lean tissue with age, and people who train or are losing weight consistently do better above it.

How much protein do women need?

The same amount per kilogram of body weight as men — protein requirements scale with body size and activity, not sex. Because women are on average smaller, the resulting gram total is usually lower, but the coefficient does not change. Pregnancy and breastfeeding do raise requirements, and those situations warrant individual advice from a doctor or dietitian.

Can you eat too much protein?

In people with normal kidney function, there is little evidence that high protein intake causes harm, and controlled trials at intakes well above the RDA have not demonstrated kidney damage. This does not apply to people with existing kidney or liver disease, where protein restriction is often part of clinical management. The practical ceiling for most people is that very high intakes crowd out other foods rather than that they are dangerous.

Does it matter how much protein I eat per meal?

Yes, though less than your daily total. Muscle protein synthesis responds to a meal, peaks after one to two hours, and then returns to baseline, and the response saturates at roughly 0.4 g/kg in a single sitting. Three or four meals of 30 to 40 grams each does more for muscle retention than the same total eaten as a light breakfast and lunch followed by a very large dinner — which is how most people actually eat.

How much protein do I need after 65?

Around 1.0 to 1.2 grams per kilogram of body weight per day, which is above the RDA. Ageing muscle shows what researchers call anabolic resistance: the muscle-building response to a given dose of protein is blunted compared with a younger person. Higher intakes help offset age-related muscle loss, and requirements rise further during illness or recovery from injury.

Do I need more protein on a vegan or vegetarian diet?

Yes, roughly 10 to 20 percent more than the equivalent omnivorous target. Most plant proteins are less digestible and lower in leucine than animal sources, so someone who would aim for 120 grams on a mixed diet should aim for about 135 to 145 grams fully plant-based. You do not need to combine complementary proteins within a single meal — eating varied plant sources across the day is sufficient.