Protein Intake Calculator for Adults
This protein intake calculator turns your body weight into the adult reference amount of protein per day, shows it as a share of your calories, and lets you tally the protein you have eaten against it.
Find your reference protein amount
Example values shown; replace them with your own.
Enter your weight and age to see the reference amount.
This is not a personal target. It is the RDA-style amount for healthy adults. People who are pregnant or breastfeeding, older adults, people with kidney disease or other conditions, children, and people who train hard may be advised different amounts. Talk to a doctor or registered dietitian about your own needs.
Tally what you ate (optional; example foods shown, replace them with your own)
How the protein intake calculator works
The protein intake calculator multiplies your body weight in kilograms by 0.8 to give the adult reference amount of protein in grams per day. Pounds are converted exactly first (1 lb = 0.45359237 kg). If you add your daily calories, it also shows the share of energy that amount represents, counting 4 kcal for each gram of protein:
reference protein (g) = weight (kg) × 0.8
share of calories (%) = reference protein (g) × 4 ÷ daily calories × 100
The tally works the same way for the food you enter: servings × grams of protein per serving, added up, then divided by the reference amount to give the percentage reached. Results are rounded to one decimal place for display. The tally only reports numbers; it does not judge them.
Worked example: 65 kg adult on 2,000 kcal
For a 65 kg adult aged 30 eating 2,000 kcal a day, the reference amount is 65 × 0.8 = 52 g of protein per day. That is 52 × 4 = 208 kcal, or 10.4% of 2,000 kcal. Here is a small tally against it (label values are examples):
| Food | Servings | Protein per serving | Protein |
|---|---|---|---|
| Egg | 2 | 6.3 g | 12.6 g |
| Milk, 1 glass (250 mL) | 1 | 8.3 g | 8.3 g |
| Cooked dal, 1 bowl | 1 | 14 g | 14 g |
| Total | 34.9 g |
34.9 g is 34.9 ÷ 52 = 67.1% of the reference amount so far that day.
What is the reference amount based on?
The figure comes from the US Dietary Reference Intakes, issued by the Food and Nutrition Board of the Institute of Medicine. A review in Advances in Nutrition states that the RDA for protein for adults is 0.8 g per kilogram of body weight and has been essentially unchanged for more than 70 years. The same review notes that the acceptable macronutrient distribution range (AMDR) for protein is 10–35% of calories. The RDA is an amount for adults in general, and the AMDR is a separate range expressed as a share of energy, so the two are not the same measure. This tool uses the first as its reference and shows the second only as context for the calories you enter.
Who is this amount not for?
This protein intake calculator gives a general adult reference, not a personal target. It does not show a result under age 19. People who are pregnant or breastfeeding, older adults, people with kidney disease or other health conditions, and people who train hard may be advised different amounts, as may children. The calculator does not suggest higher or lower amounts for any goal and does not say whether what you ate is too much or too little. A doctor or registered dietitian can look at your situation and advise you.
Tips for reading labels and logging food
- Use the serving the label describes. If the panel lists protein per 100 g, our nutrition label portion calculator converts it to the portion you ate.
- Use the form you ate. Raw and cooked weights differ, so match the label to the food on your plate.
- Count each food once. Add every food and drink as its own row, with servings in whole or half amounts.
- Remember what the tally leaves out. Foods without a label are not counted unless you enter a value for them.
To compare how much protein costs in different foods, try the recipe cost calculator. For weight and height context, there is an adult BMI calculator. Our guides on a high-protein diet plan, sustainable weight loss and the nutrition in one roti give meal ideas. Used with those, the protein intake calculator is a simple way to see where a day of eating sits against the adult reference.
Sources used for this page
- Optimizing Protein Intake in Adults: Interpretation and Application of the Recommended Dietary Allowance Compared with the Acceptable Macronutrient Distribution Range (Advances in Nutrition, via PubMed Central). Supports the 0.8 g per kg RDA for adults, the 10–35% of calories AMDR and the Food and Nutrition Board as the issuing body.
Frequently Asked Questions
The US Recommended Dietary Allowance for adults is 0.8 grams of protein per kilogram of body weight per day. For a 70 kg adult that is 70 × 0.8 = 56 g a day. This calculator shows that figure as a reference, not as a personal target. Your own needs can differ with age, health, pregnancy and activity, so ask a doctor or registered dietitian.
Divide the calories from protein by your total calories. Each gram of protein is counted as 4 kcal, so 56 g is 224 kcal; on 2,000 kcal a day that is 11.2%. The US acceptable macronutrient distribution range for adult protein is 10–35% of calories. The calculator does this sum when you enter your daily calories.
Yes. Switch to pounds and enter your weight; it is converted exactly to kilograms (1 lb = 0.45359237 kg) before multiplying by 0.8. A weight of 145 lb is 65.8 kg, which gives a reference amount of 52.6 g. The weight must be between 25 kg and 350 kg, or about 56 lb to 771 lb.
It is a general amount for adults aged 19 and over. People who are pregnant or breastfeeding, older adults, people with kidney disease or other conditions, and children may be advised different amounts. People who train hard may also be. Ask a doctor or registered dietitian. The tool does not show a result for anyone under 19.
Read the nutrition label and use the grams of protein for one serving, then enter how many servings you ate. Two eggs at 6.3 g each add 12.6 g. If the label lists protein per 100 g, our nutrition label calculator can work out the amount for the portion you actually ate.