acalculator

How much protein do I need a day?

Enter your weight and pick the group or goal that fits you. See the grams of protein a day, with the range the research supports.

Your numbers

Units
Protein a day
54 g

Aim for about 54 g of protein a day (0.8 g per kg of body weight, or 0.36 g per lb).

Per kilogram
0.8 g per kg of body weight, or 0.36 g per lb
Calories from this protein
218

Protein a day: 54 g. Aim for about 54 g of protein a day (0.8 g per kg of body weight, or 0.36 g per lb).

This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use

How to calculate

Estimates grams of protein a day from body weight and a sourced range per kilogram: the adult RDA, older adults, pregnancy, breastfeeding, regular exercise, or building muscle.

Example with the default inputs (Weight 150 lb, Who is it for? Most adults (RDA): 0.8 g/kg): Aim for about 54 g of protein a day (0.8 g per kg of body weight, or 0.36 g per lb).

Method: Protein a day (g) = body weight (kg) × grams per kilogram for the goal; ranges use their middle value.

  • Grams per kilogram a day: most adults 0.8 (RDA); 65 and older 1.0 to 1.2; pregnant 1.1; breastfeeding 1.3; regular exercise 1.4 to 2.0; building muscle 1.6 to 2.2.
  • The daily figure is the middle of the range; the low and high ends are shown too.
  • Weight is total body weight. For people with a lot of body fat, a dietitian may use a lower reference weight.
  • Protein gives 4 calories per gram.
  • This is an estimate for planning, not medical advice.

Machine-readable copies: Markdown, JSON.

Worked examples

Each example is checked against the calculator on every build.

  1. Weight 150 lb, Who is it for? Most adults (RDA): 0.8 g/kg gives Protein a day 54 g, Per kilogram 0.8 g per kg of body weight, or 0.36 g per lb, Calories from this protein 217.724338.Source: IOM 2005 protein RDA, 0.8 g/kg a day; hand calculation in content.mdx
  2. Weight 154.3 lb, Who is it for? Regular exercise: 1.4 to 2.0 g/kg gives Protein a day 119 g, Range from 98 g, Range up to 140 g, Calories from this protein 476.Source: ISSN position stand (Jäger et al. 2017), 1.4 to 2.0 g/kg a day; hand calculation in content.mdx
  3. Weight 176.4 lb, Who is it for? Adults 65 and older: 1.0 to 1.2 g/kg gives Protein a day 88 g, Range from 80 g, Range up to 96 g.Source: PROT-AGE Study Group (Bauer et al. 2013), 1.0 to 1.2 g/kg a day; hand calculation in content.mdx
  4. Weight 143.3 lb, Who is it for? Pregnant: 1.1 g/kg gives Protein a day 71 g, Per kilogram 1.1 g per kg of body weight, or 0.50 g per lb.Source: IOM 2005 protein RDA in pregnancy, 1.1 g/kg a day; hand calculation in content.mdx
  5. Weight 200 lb, Who is it for? Building muscle: 1.6 to 2.2 g/kg gives Protein a day 172 g, Range from 145 g, Range up to 200 g.Source: Morton et al. 2018 (gains plateau at 1.62 g/kg, 95% CI up to 2.20); hand calculation in content.mdx

How it works

Protein a day (grams) = body weight (kilograms) × grams per kilogram for your group or goal.

  • Most adults (RDA): 0.8 g per kg a day (Institute of Medicine, 2005)

  • Adults 65 and older: 1.0 to 1.2 g per kg a day (PROT-AGE Study Group, 2013)

  • Pregnant (second half of pregnancy): 1.1 g per kg a day (Institute of Medicine, 2005)

  • Breastfeeding: 1.3 g per kg a day (Institute of Medicine, 2005)

  • Regular exercise: 1.4 to 2.0 g per kg a day (ISSN position stand, 2017)

  • Building muscle with weight training: 1.6 to 2.2 g per kg a day (Morton and others, 2018)

  • Where the source gives a range, the headline uses the middle of it ((low + high) ÷ 2), and the calculator also shows the low and high ends: weight × low and weight × high.

  • The calculator shows the rate per kilogram and per pound (grams per kg × 0.45359237, to two decimals).

  • Calories from the protein = grams × 4.

Weight in pounds is changed to kilograms first: 1 lb = 0.45359237 kg.

Assumptions

  • The ranges are for adults. Children and teens have their own RDAs by age.
  • Weight is your total body weight. For people with a lot of body fat, a dietitian may base protein on a lower reference weight.
  • The pregnancy RDA applies to the second half of pregnancy; in the first half the needs are close to the adult RDA.
  • This calculator gives an estimate for planning. It is not medical advice. Ask a doctor or a registered dietitian about protein if you have kidney or liver disease, or another health condition.

Worked examples by hand

150 lb, most adults. 150 × 0.45359237 = 68.039 kg. Protein = 68.039 × 0.8 = 54.43 g a day (0.36 g per lb), which is 54.43 × 4 = 217.7 calories.

70 kg, regular exercise. Range: 70 × 1.4 = 98 g to 70 × 2.0 = 140 g. Middle: 70 × 1.7 = 119 g a day, 476 calories.

80 kg, aged 65 or older. Range: 80 × 1.0 = 80 g to 80 × 1.2 = 96 g. Middle: 80 × 1.1 = 88 g a day.

65 kg, pregnant. 65 × 1.1 = 71.5 g a day (0.50 g per lb).

200 lb, building muscle. 200 × 0.45359237 = 90.718 kg. Range: 90.718 × 1.6 = 145.15 g to 90.718 × 2.2 = 199.58 g. Middle: 90.718 × 1.9 = 172.37 g a day.

Other questions people ask

How much protein do I need a day?

The Recommended Dietary Allowance (RDA) for adults is 0.8 grams of protein per kilogram of body weight a day, or about 0.36 grams per pound. At 150 lb (68 kg), that is about 54 grams a day. The RDA is set to cover the needs of nearly all healthy adults.

How much protein do I need if I exercise?

The International Society of Sports Nutrition (2017) says 1.4 to 2.0 grams per kilogram a day is enough for most people who exercise. At 70 kg that is 98 to 140 grams, and the calculator shows the middle, 119 grams.

How much protein do I need to build muscle?

A 2018 meta-analysis of weight-training trials found that muscle gains from weight training stopped rising above about 1.6 grams per kilogram a day, with an upper estimate of 2.2. The calculator uses 1.6 to 2.2 grams per kilogram for this goal.

Do older adults need more protein?

The PROT-AGE Study Group (2013) recommends 1.0 to 1.2 grams per kilogram a day for healthy people aged 65 and older, more than the adult RDA, to help keep muscle and strength. People with some illnesses may need more, and people with severe kidney disease may need less, so ask a doctor.

How much protein do I need when pregnant or breastfeeding?

The National Academies set the RDA at 1.1 grams per kilogram a day during pregnancy (for the second half) and 1.3 grams per kilogram a day while breastfeeding.

Can I eat too much protein?

For healthy adults, the National Academies set no upper limit for protein, and its acceptable range goes up to 35% of calories. People with kidney disease should follow their doctor's advice on protein.