0.8 grams per kilogram (kg) of body weight per day is the RDA for protein. This is the Recommended Dietary Allowance (RDA) set by health authorities including the World Health Organization (WHO), the Indian Council of Medical Research (ICMR), and the US National Institutes of Health (NIH). It meets the daily protein needs of 97–98% of healthy adults and prevents deficiency.
RDA is a minimum threshold, not an optimal target. This guide breaks the number down by body weight, life stage, and activity level, and shows how to hit a personalized target using our protein intake calculator.
The RDA Protein Formula
For readers working in pounds, divide weight in lb by 2.2 to get kg, then multiply by 0.8.
Examples:
The RDA protein formula produces different daily targets depending on body weight. A few examples:
- RDA protein for 50 kg (110 lb): 50 × 0.8 = 40g
- RDA protein for 70 kg (154 lb): 70 × 0.8 = 56g
- RDA protein for 90 kg (198 lb): 90 × 0.8 = 72g
RDA Protein by Body Weight
Body weight is the main driver of RDA protein. Here’s how the numbers break down at the standard 0.8 g/kg rate, alongside a higher activity target of 1.6 g/kg:
| Body weight | RDA (0.8 g/kg) | Active target (1.6 g/kg) |
|---|---|---|
| RDA protein for 40 kg (88 lb) | 32g | 64g |
| RDA protein for 45 kg (99 lb) | 36g | 72g |
| RDA protein for 50 kg (110 lb) | 40g | 80g |
| RDA protein for 55 kg (121 lb) | 44g | 88g |
| RDA protein for 60 kg (132 lb) | 48g | 96g |
| RDA protein for 65 kg (143 lb) | 52g | 104g |
| RDA protein for 70 kg (154 lb) | 56g | 112g |
| RDA protein for 75 kg (165 lb) | 60g | 120g |
| RDA protein for 80 kg (176 lb) | 64g | 128g |
| RDA protein for 85 kg (187 lb) | 68g | 136g |
| RDA protein for 90 kg (198 lb) | 72g | 144g |
| RDA protein for 95 kg (209 lb) | 76g | 152g |
| RDA protein for 100 kg (220 lb) | 80g | 160g |
| RDA protein for 105 kg (231 lb) | 84g | 168g |
| RDA protein for 110 kg (243 lb) | 88g | 176g |
RDA by Life Stage and Activity
Protein needs vary by age, reproductive status, and activity level. There are 5 main groups with adjusted protein targets: children, pregnant and lactating women, older adults, athletes, and people recovering from illness or surgery.
| Group | g/kg body weight | 70 kg example |
|---|---|---|
| Sedentary adult | 0.8 | 56g |
| Older adult (65+) | 1.0–1.2 | 70–84g |
| Pregnancy / lactation | ~1.1 (+25g) | 77g+ |
| Athlete / strength training | 1.2–2.0 | 84–140g |
| Illness / surgical recovery | 1.2–2.0 | 84–140g |
- Infants need up to 1.5 g/kg during rapid early growth, tapering to adult levels by adolescence.
- Pregnant and lactating women need an additional 25 grams of protein per day above baseline RDA to support fetal growth and milk production.
- Older adults benefit from 1.0–1.2 g/kg, above the standard RDA, to offset age-related muscle loss.
RDA vs. Optimal Intake
RDA protein is a minimum threshold, not an optimal target.
The 0.8 g/kg figure prevents deficiency in the general population — it does not account for muscle building, athletic performance, or age-related muscle preservation.
| Goal | Target (g/kg) |
|---|---|
| Prevent deficiency (RDA) | 0.8 |
| Preserve muscle in a calorie deficit | 1.2–1.6 |
| Build muscle with resistance training | 1.6–2.2 |
Protein needs rise during a calorie deficit to preserve muscle mass. Someone cutting calories for weight loss typically needs more protein per kg than standard RDA suggests.
RDA Protein Calculator
At 0.8 g/kg, a 70 kg (154 lb) adult on a sedentary lifestyle needs 56 grams of protein per day. Athletes, older adults, and pregnant or lactating women need more — often between 1.0 and 2.0 g/kg.
Rather than running the calculation by hand for your own weight and activity level, use the protein intake calculator to get a personalized daily target and a per-meal breakdown.
Not sure which multiplier fits you? Sedentary adults use 0.8 g/kg, older adults use 1.0–1.2 g/kg, and athletes use 1.2–2.0 g/kg depending on training intensity.
Common Calculation Mistakes
There are 3 common mistakes people make when calculating RDA protein: using total weight instead of lean mass, ignoring calorie deficit effects, and ignoring protein quality.
Using total body weight instead of lean body mass overestimates needs for people with higher body fat and underestimates needs for very muscular individuals.
Ignoring calorie deficit effects misses that cutting calories raises protein needs, often into the 1.2–1.6 g/kg range. Ignoring protein quality overlooks that RDA figures assume complete proteins — plant-based diets may need higher total intake or complementary sources to match the same functional requirement.
