Free Protein Calculator
Work out how much protein you need per day from your weight, goal and age, with adjustments for strength training and GLP-1 medications. Same formula as the Protein Pal app.
Medical Disclaimer
This calculator provides general nutritional guidance based on scientific research. Before making any significant changes to your diet or protein intake, especially if you have existing health conditions, kidney problems, or are pregnant or breastfeeding, please consult with a qualified healthcare provider, registered dietitian, or your doctor. Individual needs may vary based on your specific health circumstances.
How the Calculator Works
The calculator uses the same rules as the Protein Pal app. It multiplies your body weight in kilograms by a number of grams per kg, chosen in four steps:
- Your goal sets the starting point: 0.38g/lb (0.83g/kg) for general health, 0.54g/lb (1.2g/kg) to lose weight and keep muscle, and 0.73g/lb (1.6g/kg) to build muscle.
- From age 65, general health rises to 0.45g/lb (1.0g/kg).
- Strength training twice a week or more lifts any goal to at least 0.73g/lb (1.6g/kg).
- A GLP-1 medication sets a minimum of 0.54g/lb (1.2g/kg). It raises a lower goal but never lowers a higher one.
If you enter pounds, the calculator converts to kilograms first (1lb = 0.4536kg) and rounds the final answer to the nearest gram.
Daily Protein by Body Weight
| Body weight | General health (0.83g/kg) | General health, 65+ (1.0g/kg) | Lose weight or GLP-1 (1.2g/kg) | Build muscle or strength train (1.6g/kg) |
|---|---|---|---|---|
| 120lb (54kg) | 45g | 54g | 65g | 87g |
| 140lb (64kg) | 53g | 64g | 76g | 102g |
| 160lb (73kg) | 60g | 73g | 87g | 116g |
| 180lb (82kg) | 68g | 82g | 98g | 131g |
| 200lb (91kg) | 75g | 91g | 109g | 145g |
| 220lb (100kg) | 83g | 100g | 120g | 160g |
| 240lb (109kg) | 90g | 109g | 131g | 174g |
| 260lb (118kg) | 98g | 118g | 142g | 189g |
| 280lb (127kg) | 105g | 127g | 152g | 203g |
| 300lb (136kg) | 113g | 136g | 163g | 218g |
The Research Behind Each Number
General health: 0.38g/lb (0.83g/kg)
This is the World Health Organization recommended intake for healthy adults (WHO/FAO/UNU, 2007). It covers basic needs for most people who are not trying to change their body composition.
General health from age 65: 0.45g/lb (1.0g/kg)
Muscle responds less to protein with age, so expert groups recommend more for older adults: at least 1.0 to 1.2g/kg a day (Bauer et al., PROT-AGE Study Group, JAMDA, 2013; Deutz et al., ESPEN, Clinical Nutrition, 2014). The calculator uses the 1.0g/kg lower end.
Lose weight and keep muscle: 0.54g/lb (1.2g/kg)
In a calorie deficit, more protein helps you hold on to muscle while you lose fat. A review in the American Journal of Clinical Nutrition recommends 1.2 to 1.6g/kg a day for weight loss and keeping it off (Leidy et al., American Journal of Clinical Nutrition, 2015), and the 2025 joint advisory from four US nutrition and obesity societies notes the same range (Mozaffarian et al., American Journal of Clinical Nutrition, 2025). The calculator uses the 1.2g/kg lower bound. Our weight loss protein calculator goes into more detail.
Build muscle: 0.73g/lb (1.6g/kg)
A meta-analysis of 49 trials found that protein added muscle up to about 1.6g/kg a day, with little extra benefit beyond it, and an upper confidence limit around 2.2g/kg (Morton et al., British Journal of Sports Medicine, 2018). See the muscle gain protein calculator for how to hit it.
Strength training twice a week or more: at least 0.73g/lb (1.6g/kg)
The trials behind the 1.6g/kg figure only included people training at least twice a week, the same minimum the WHO recommends for muscle strengthening (Bull et al., WHO 2020 guidelines, British Journal of Sports Medicine). If you train that often, your muscle can use the extra protein whatever your goal, so the calculator uses at least 1.6g/kg. For people losing weight, 1.6g/kg is also the top of the recommended weight loss range.
GLP-1 medications: at least 0.54g/lb (1.2g/kg)
Semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) cut appetite so effectively that protein intake often falls with everything else, and a meaningful share of the weight lost can be muscle. A 2025 expert consensus recommends 1.2 to 1.5g/kg of body weight a day during GLP-1 weight loss to preserve lean mass (Sievenpiper et al., Obesity Pillars, 2025). The calculator uses 1.2g/kg as a minimum, or 1.6g/kg if you build muscle or strength train. For medication specific guidance, see the GLP-1 protein calculator, Ozempic, Wegovy, Mounjaro and Zepbound versions.
How to Use Your Number
- Spread it out. Three or four meals of 25 to 40g each is easier than one big protein dinner (Schoenfeld and Aragon, Journal of the International Society of Sports Nutrition, 2018).
- Start with the protein on your plate. Build each meal around a protein source, then add the rest.
- Round up, not down. These are minimums for your situation, and going a little over is fine for healthy adults (Antonio et al., Journal of the International Society of Sports Nutrition, 2016).
- Recalculate when things change: your weight, your training, a new medication or a birthday past 65.
Large single meals are not wasted either: a 2023 study found the body kept using protein from a 100g dose for over 12 hours (Trommelen et al., Cell Reports Medicine, 2023). Total daily intake matters most.
Hit Your Number Every Day
Knowing your target is the easy part. Protein Pal uses this same formula, then makes logging each meal take seconds so you can see whether you hit it. It is free to download on iPhone and Android, and manual logging is free.
For more reading, see how much protein you need per day and how to calculate your protein needs.
Common Questions
- How much protein do I need per day?
- It depends on your body weight and goal. The calculator uses 0.38g per lb (0.83g/kg) for general health, 0.45g/lb (1.0g/kg) for general health from age 65, 0.54g/lb (1.2g/kg) to lose weight and keep muscle, and 0.73g/lb (1.6g/kg) to build muscle. For a 160lb (73kg) adult that is about 60g, 73g, 87g or 116g a day.
- How do I calculate my protein needs?
- Convert your weight to kilograms (pounds × 0.4536) and multiply by the grams per kg for your situation: 0.83 for general health, 1.0 for general health at 65 or over, 1.2 to lose weight or on a GLP-1, and 1.6 to build muscle or if you strength train twice a week or more.
- Why does strength training change my protein target?
- The trials behind the 1.6g/kg muscle building figure were in people who did resistance training at least twice a week, and the WHO recommends muscle strengthening on two or more days a week. If you train that often, the calculator uses at least 0.73g/lb (1.6g/kg), even if your goal is weight loss or general health.
- Do older adults need more protein?
- Yes. The PROT-AGE Study Group and ESPEN recommend at least 1.0 to 1.2g/kg a day for healthy adults over 65, above the 0.83g/kg general recommendation, because muscle responds less to protein with age. Enter your age and the calculator uses 1.0g/kg for general health from 65.
- How much protein do I need on a GLP-1 like Ozempic or Mounjaro?
- At least 0.54g per lb (1.2g/kg) a day. A 2025 expert consensus recommends 1.2 to 1.5g/kg during GLP-1 weight loss to preserve muscle. Ticking the GLP-1 box never lowers your target: if you build muscle or strength train, it stays at 1.6g/kg.
- Can I eat too much protein?
- For healthy adults with normal kidney function, intakes well above these targets have been studied without harm. Above about 1.6g/kg there is little extra benefit for muscle, and 2.2g/kg is the top of the useful range. If you have kidney disease, ask your doctor first.
- Does protein timing matter?
- Total daily intake matters most. Spreading it over three or four meals of 25 to 40g each makes the target easier to hit and suits muscle building, but recent research shows the body keeps using protein from a large meal for many hours, so there is no need to stress about exact timing.