How to Calculate Your Protein Needs: The Formula, Step by Step
Your daily protein target in four steps: weight, goal, adjustments for age, training or GLP-1 medication, then multiply. Worked examples for five people and how to split the total across meals.
The formula is simple: body weight × multiplier = grams of protein per day. The only real decision is the multiplier, and that depends on your goal, your age, whether you strength train and whether you take a GLP-1 medication.
The four steps below use the same rules as our protein calculator and the Protein Pal app. For the research behind each number, see how much protein per day.
Step 1: Take Your Body Weight
Use your current weight in pounds or kilograms. If you have a lot of weight to lose, a target based on current weight can be very high; a doctor or dietitian may suggest using an adjusted or goal weight instead.
Step 2: Pick the Multiplier for Your Goal
| Goal | Per pound | Per kilogram | Basis |
|---|---|---|---|
| General health | 0.38g | 0.83g | WHO safe intake for adults WHO/FAO/UNU, 2007 |
| Lose weight and keep muscle | 0.54g | 1.2g | Weight loss research Leidy et al., American Journal of Clinical Nutrition, 2015 |
| Build muscle | 0.73g | 1.6g | Where muscle gains level off Morton et al., British Journal of Sports Medicine, 2018 |
Step 3: Check the Adjustments
Each of these can raise your multiplier. If more than one applies, use the highest.
- Age 65 or over: general health rises to 0.45g/lb (1.0g/kg) Bauer et al., PROT-AGE Study Group, JAMDA, 2013.
- Strength training two or more times a week: use at least 0.73g/lb (1.6g/kg), whatever your goal.
- On a GLP-1 medication (Ozempic, Wegovy, Mounjaro, Zepbound): use at least 0.54g/lb (1.2g/kg) Sievenpiper et al., Obesity Pillars, 2025.
Step 4: Multiply
| Person | Multiplier | Daily target |
|---|---|---|
| A 155lb woman losing weight who does light weights twice a week | Strength training twice a week raises her to 1.6g/kg | 112g (70.3kg × 1.6) |
| A 185lb man building muscle | Build muscle is 1.6g/kg | 134g (83.9kg × 1.6) |
| A 200lb man who wants general health and does not train | General health is 0.83g/kg | 75g (90.7kg × 0.83) |
| A 68 year old woman, 150lb, general health | At 65 or over, general health rises to 1.0g/kg | 68g (68.0kg × 1.0) |
| A 220lb woman on Zepbound, general health | The GLP-1 minimum raises her to 1.2g/kg | 120g (99.8kg × 1.2) |
Working in kilograms? Multiply your weight in kg by the g/kg figure. 80kg × 1.2 = 96g.
Step 5: Split It Across Your Meals
Spreading protein across the day is easier than eating it all at dinner, and keeps you fuller.
| Daily target | 3 meals | 4 meals |
|---|---|---|
| 80g | 27g each | 20g each |
| 100g | 33g each | 25g each |
| 130g | 43g each | 33g each |
| 160g | 53g each | 40g each |
If a meal is hard to push past 30g, add a high protein snack or a shake. More on per meal amounts in how much protein you can absorb per meal.
What Your Target Looks Like in Food
Here is about 170g, close to the muscle building target for a 230lb person (167g), using USDA values:
| Meal | Food | Protein |
|---|---|---|
| Breakfast | 3 large eggs and 1 cup nonfat Greek yogurt | 44g |
| Lunch | 6oz cooked chicken breast | 53g |
| Snack | 1 cup 1% cottage cheese | 28g |
| Dinner | 150g cooked lean top sirloin | 44g |
| Total | 169g |
Common Mistakes
- Treating the RDA as a target. 0.8g/kg (0.36g/lb) is set to prevent deficiency. It is a sensible floor for general health, not for losing weight or building muscle.
- Ignoring strength training. Lifting twice a week is enough to justify 0.73g/lb (1.6g/kg), even if your goal is weight loss.
- Forgetting the age adjustment. After 65, 0.45g/lb (1.0g/kg) is the minimum for general health.
- Not checking. Most people guess their protein intake wrong. Track for a week with one of the best protein tracker apps to see where you really are.
Skip the Maths
The protein calculator does all four steps in a few seconds. Protein Pal uses the same rules to set your goal in the app, then tracks your progress each day. It is free to download, and manual logging is free. Photo scanning is part of Pro. Available on iPhone and Android.
Related Reading
Frequently Asked Questions
- What is the formula for daily protein?
- Body weight × multiplier. Use 0.38g per lb for general health, 0.54g when losing weight and 0.73g when building muscle or strength training. In kilograms the multipliers are 0.83, 1.2 and 1.6.
- How do I calculate protein in grams per pound?
- Multiply your weight in pounds by your multiplier. A 160lb person losing weight: 160 × 0.54 = about 87g per day.
- How do I convert g/kg to g/lb?
- Multiply the g/kg figure by 0.4536, or divide by 2.2. So 1.6g/kg is 0.73g/lb and 1.2g/kg is 0.54g/lb.
- Do I calculate protein from my current or goal weight?
- Most guidance uses current weight. With a lot of weight to lose, current weight can give a very high target, so a goal or adjusted weight may be more practical. Ask your doctor or dietitian if unsure.
- Does age change how much protein I need?
- Yes. Adults 65 and over should aim for at least 0.45g/lb (1.0g/kg) for general health, compared with 0.38g/lb (0.83g/kg) for younger adults.