Most healthy adults need at least 0.8 grams of protein per kilogram of body weight per day, about 0.36 grams per pound. That is the Recommended Dietary Allowance (RDA) set by the National Academies and used by the NIH and the Dietary Guidelines for Americans. A 150-pound adult needs at least 54 grams a day. Many people benefit from more: 1.2 to 2.0 g/kg for regular exercisers, people in a calorie deficit and athletes, and about 1.0 to 1.2 g/kg for adults over 65.
The protein formula
To convert pounds to kilograms, multiply by 0.4536. Or work in pounds directly: 0.8 g/kg equals 0.36 g/lb, and 1.6 g/kg equals about 0.73 g/lb.
Example: 150 lb = 68.0 kg.
| Target | Factor | Daily protein |
|---|---|---|
| RDA minimum | 0.8 g/kg | 54 g |
| Active adult | 1.2 g/kg | 82 g |
| Weight loss or strength training | 1.6 g/kg | 109 g |
The protein intake calculator applies these factors by goal and activity level.
Protein factors by situation
| Situation | Suggested intake | Source or basis |
|---|---|---|
| Healthy, sedentary adult | 0.8 g/kg (RDA) | National Academies |
| Regular exercise | 1.0–1.6 g/kg | Sports nutrition consensus |
| Athletes and strength training | 1.2–2.0 g/kg | Joint position of the American College of Sports Medicine, the Academy of Nutrition and Dietetics and Dietitians of Canada |
| Losing weight (calorie deficit) | 1.2–1.6 g/kg, up to about 2.0 for lean athletes | Helps preserve lean mass |
| Adults 65 and older | 1.0–1.2 g/kg | Expert groups on aging, to offset muscle loss |
| Pregnancy (2nd half) and breastfeeding | 1.1 g/kg, about 71 g/day | National Academies RDA |
| Chronic kidney disease | Often lower | Individualized medical advice |
Protein should also fit within the National Academies’ acceptable range of 10% to 35% of calories. On an 1,800-calorie diet, that is 45 to 158 grams.
Daily protein by body weight
| Body weight | kg | RDA (0.8 g/kg) | Active (1.2 g/kg) | Training or dieting (1.6 g/kg) | Upper typical (2.0 g/kg) |
|---|---|---|---|---|---|
| 120 lb | 54.4 | 44 g | 65 g | 87 g | 109 g |
| 140 lb | 63.5 | 51 g | 76 g | 102 g | 127 g |
| 160 lb | 72.6 | 58 g | 87 g | 116 g | 145 g |
| 180 lb | 81.6 | 65 g | 98 g | 131 g | 163 g |
| 200 lb | 90.7 | 73 g | 109 g | 145 g | 181 g |
| 220 lb | 99.8 | 80 g | 120 g | 160 g | 200 g |
| 250 lb | 113.4 | 91 g | 136 g | 181 g | 227 g |
When body weight overstates your needs
Protein needs track lean mass more closely than total weight. For someone with a lot of body fat, multiplying total weight by 1.6 or 2.0 g/kg can give an unrealistically high target. Two alternatives:
- Goal or reference weight: a 5′6″, 260-pound person might use the weight at a BMI of 25, about 155 lb (70.3 kg). At 1.2 g/kg, that is about 84 g, versus about 142 g using total weight.
- Lean body mass: multiply lean mass by about 1.6 to 2.2 g/kg. Estimate it with the lean body mass calculator, or see how to measure body fat percentage.
Spreading protein through the day
Research on muscle protein synthesis suggests that about 0.3 to 0.4 g/kg per meal, roughly 20 to 40 grams for most adults, spread over three or four meals, is a practical pattern. Older adults may need the higher end per meal. A 109-gram target could be breakfast 25 g, lunch 30 g, snack 20 g and dinner 34 g.
How much protein is in common foods?
Approximate values per typical serving, based on USDA nutrient data:
| Food | Serving | Protein |
|---|---|---|
| Chicken breast, cooked | 3 oz (85 g) | about 26 g |
| Salmon, cooked | 3 oz | about 22 g |
| Canned tuna, drained | 3 oz | about 20 g |
| Lean ground beef, cooked | 3 oz | about 22 g |
| Plain Greek yogurt, nonfat | 7 oz (200 g) | about 20 g |
| Lentils, cooked | 1 cup | about 18 g |
| Firm tofu | ½ cup | about 20 g |
| Egg | 1 large | about 6 g |
| Milk | 1 cup | about 8 g |
| Peanut butter | 2 tablespoons | about 7 g |
| Almonds | 1 oz (about 23 nuts) | about 6 g |
Check labels for the products you buy, since brands vary. Plant proteins can fully meet needs when you eat a variety of sources across the day.
Do you need protein powder?
Usually not. Most people can reach even a 1.6 g/kg target with food, especially by adding a protein source to every meal. Powders and shakes are simply a convenient option when appetite, time or travel make that hard. A typical scoop of whey or plant protein supplies roughly 20 to 25 grams, but amounts vary by product. Keep in mind that the FDA does not approve dietary supplements for safety or effectiveness before they are sold, so look for products verified by an independent testing program, and check the label for added sugars and the actual protein per serving. Whole foods also bring fiber, vitamins and minerals that powders lack.
Protein and calories
Protein provides 4 calories per gram. A 109-gram target supplies 436 calories, about 24% of an 1,800-calorie diet. To fit protein alongside carbohydrate and fat within your calorie budget, see how to calculate macros or use the macro calculator. When cutting calories for weight loss, raising protein is one of the most reliable ways to protect muscle and control hunger, as covered in how to calculate calories for weight loss.
Signs you may be short, and when to be careful
Low protein intake is uncommon in the US, but it can occur with very low calorie diets, restrictive eating, illness or in some older adults with low appetite. Unintended muscle loss and slow recovery from injury can be signs. On the other side, people with kidney disease, liver disease or certain metabolic disorders should not raise protein without medical guidance.
This guide is general nutrition information, not medical advice. Protein needs vary with health conditions, medications, pregnancy and activity. Ask a doctor or registered dietitian for a personalized target, especially if you have kidney disease.
Frequently asked questions
How much protein do I need a day?
The Recommended Dietary Allowance for healthy adults is 0.8 grams per kilogram of body weight, or about 0.36 grams per pound. A 150-pound adult needs at least about 54 grams a day. Active adults, older adults and people losing weight often do better with 1.2 to 2.0 g/kg.
Is the RDA for protein enough?
It is enough to prevent deficiency in nearly all healthy, sedentary adults. It is a minimum, not an optimal target for everyone. Sports nutrition organizations recommend 1.2 to 2.0 g/kg for athletes, and experts on aging often suggest 1.0 to 1.2 g/kg for adults over 65.
Can you eat too much protein?
No tolerable upper intake level has been set for protein. Intakes up to about 2 g/kg appear safe for healthy adults. People with chronic kidney disease may need to limit protein and should follow their doctor's or dietitian's advice.
How much protein do I need during pregnancy?
The RDA rises to 1.1 g/kg of pre-pregnancy weight, or about 71 grams a day, during the second half of pregnancy and while breastfeeding, according to the National Academies.
Should I use my current weight or goal weight?
For most people, current weight works. If you have a high body fat percentage, basing protein on goal weight, an adjusted weight or lean body mass avoids an unnecessarily high target.