Why the advice seems to disagree
Look up protein needs and you'll find 0.8 g/kg, 1.2 to 1.6 g/kg, 1.4 to 2.0 g/kg and even higher. They aren't in conflict. Each one answers a different question for a different group of people.
The 0.8 figure is the adult RDA, the amount that covers the basic needs of nearly all healthy adults. The 1.2 to 1.6 range comes from the 2025-2030 Dietary Guidelines as a general daily goal. The 1.4 to 2.0 range is what sports nutrition researchers describe for people who exercise regularly.
Which number fits you
If you're healthy and not training hard, the guideline range is a sensible place to aim. The RDA is the floor, not the goal. If you lift or train most days, the exercise range is built for you.
Going higher has limits. A meta-analysis of resistance-training studies found that, on average, extra protein stopped adding to muscle gains at about 1.62 g/kg a day. The exception is dieting: the ISSN says resistance-trained people may need 2.3 to 3.1 g/kg to keep lean mass during a calorie deficit.
- Healthy adult, light activity: 1.2 to 1.6 g/kg
- Regular training: 1.4 to 2.0 g/kg
- Trained and in a calorie deficit: up to 2.3 to 3.1 g/kg
- Minimum to cover basic needs: 0.8 g/kg
Turning g/kg into grams
Convert your weight to kilograms by dividing pounds by 2.2046. Then multiply by both ends of your range. A 180 lb person weighs about 81.6 kg, so the guideline range is 98 to 131 g a day.
Don't just use the midpoint. A range shows you have room. Landing at 100 g one day and 125 g the next is fine. Our protein calculator does the conversion and also shows the per-meal split and calories.
Formula notes
Kilograms = pounds / 2.2046Daily protein = kilograms x g/kg rate
Three worked cases
A 140 lb office worker who walks a few times a week weighs 63.5 kg. The guideline range gives 76 to 102 g a day, and the RDA floor is 51 g.
A 200 lb lifter training five days a week weighs 90.7 kg. The exercise range gives 127 to 181 g. Past about 147 g (1.62 g/kg), the meta-analysis suggests extra protein adds little for muscle.
A 160 lb lifter who is cutting weighs 72.6 kg. At the ISSN dieting range of 2.3 to 3.1 g/kg, that's about 167 to 225 g a day. That's a lot of food, so it's worth checking with a sports dietitian first.
What hitting 120 grams looks like
Numbers on a screen are easy. Eating them takes a plan. Spreading protein over three or four meals makes a higher target manageable, and the ISSN discusses 20 to 40 g per serving for people who exercise.
Check the label or a nutrition database for the foods you eat, since portions vary a lot. Mixing animal and plant sources, like eggs, fish, dairy, beans, lentils and soy, also brings fiber and other nutrients that a gram count doesn't track.
Common mistakes
The most common is mixing units. Multiplying pounds by a g/kg rate more than doubles the answer. A 180 lb person at 1.6 "per kg" using pounds gets 288 g instead of 131 g.
Another is treating 30 g as the most your body can absorb at once. Digestion doesn't stop there. The last is judging your intake from one day of logging. Look at several typical days before deciding you're short.
Frequently asked questions
Do older adults need more protein?
Needs can change with age, illness and activity, and the general references here aren't tailored by age. Ask a doctor or dietitian if you're unsure.
Does protein damage healthy kidneys?
The National Academies found too little evidence to set an upper limit for protein. People who already have kidney disease should follow their care team's advice.
Can vegetarians get enough protein?
Yes. Beans, lentils, soy, dairy, eggs, nuts and seeds can cover it. Variety across the day helps you get a full mix of amino acids.
Is it OK to eat most of my protein at dinner?
Your daily total matters most. Spreading it out can help if you train, but uneven meals still count toward the total.
References
These sources support the method or guidance used for Protein Calculator. Verify time-sensitive rules at the source.
Try the calculator
Open Protein Calculator, enter your scenario, and compare its supporting rows with this guide's method and checks.