Protein Calculator

How it works

Protein needs are usually expressed per kilogram of body weight:

Protein (g/day) = body weight (kg) × g/kg

Spreading protein through the day

The ISSN suggests spreading intake across meals, around 0.25 g/kg (roughly 20–40 g) per meal, every 3–4 hours. Good sources include poultry, fish, eggs, dairy, legumes, tofu and tempeh.

Protein while losing weight

In a calorie deficit, protein toward the upper part of the range, with resistance training, helps preserve muscle. Use the Macro Calculator to fit your protein into a calorie target.

If you have a lot of weight to lose

For people with obesity, using total body weight can overestimate needs. Some dietitians use an adjusted or goal body weight instead.

Protein in common foods

Approximate protein per typical serving (values vary by brand and preparation):

A day with Greek yogurt at breakfast, a chicken salad at lunch, a handful of nuts and a salmon dinner reaches roughly 90–100 g without supplements.

Plant-based protein

Vegetarians and vegans can meet protein needs with legumes, soy foods, seitan, whole grains, nuts and seeds. Plant proteins are often a little lower in some essential amino acids (for example lysine in grains) and slightly less digestible, so eating a variety of sources across the day — and aiming toward the middle or top of your range — is a practical approach.

Older adults

Muscle mass and strength naturally decline with age, and research suggests many older adults benefit from more than the 0.8 g/kg RDA, especially when combined with resistance exercise. If you are over 65, or recovering from illness or surgery, ask your doctor or dietitian what target suits you.

Protein and timing

Total daily protein matters most. Beyond that, spreading it fairly evenly over three or four meals, and including some protein in the meal after a workout, is a sensible habit. Before bed, a protein-rich snack such as cottage cheese or yogurt is a common strategy among athletes, though it's not necessary for most people.

Grams per pound vs. per kilogram

Fitness advice often uses grams per pound. To convert, divide g/kg by 2.2: 1.6 g/kg is about 0.73 g/lb, and 2.0 g/kg is about 0.9 g/lb. The popular "1 gram per pound" rule (2.2 g/kg) is above what the ISSN finds necessary for most people, but it is a simple upper bound for those who prefer it.

Signs you may need more protein

Low protein intake over time can contribute to loss of muscle, slow recovery from exercise or injury, and feeling hungry soon after meals. Most adults in high-income countries meet the RDA, but people eating very little, older adults and those on restrictive diets are more likely to fall short.

Worked examples

Example 1: 180 lb, regular exercise

180 lb = 81.6 kg. 81.6 × 1.2–1.6 = 98–131 g/day. RDA minimum: 65 g.

Example 2: 60 kg, mostly sedentary

60 × 0.8–1.0 = 48–60 g/day.

Limitations

• Ranges are general; older adults and athletes may need more, some medical conditions less.
• Based on total body weight, which can overestimate needs with higher body fat.

Who should not rely on this calculator

People with chronic kidney disease or liver disease should not increase protein without medical advice. Pregnant or breastfeeding people, children and teens have different requirements.