Protein Calculator
Get your personalised daily protein target in grams based on your weight, goal, and activity level, then distribute it across your meals.
🥩 What is a Protein Calculator?
A protein calculator estimates how many grams of dietary protein you should eat each day based on your body weight, fitness goal, and activity level. It applies evidence-based multipliers derived from research by the International Society of Sports Nutrition (ISSN), the American College of Sports Medicine (ACSM), and the Institute of Medicine to give you a personalised range rather than a generic number.
Common use cases include planning a muscle-building diet, maintaining lean mass during a fat-loss phase, supporting athletic recovery, ensuring adequate protein intake for older adults (who need more protein than the population average to prevent sarcopenia), and building a daily macro budget for calorie tracking. The Meal Distribution mode helps you split a daily protein target across your actual meal schedule, so each meal provides enough leucine to stimulate muscle protein synthesis.
A widespread misconception is that the government RDA of 0.8 g/kg is an optimal target. It is actually a minimum to prevent deficiency in sedentary adults, not a recommendation for people who exercise. Active individuals, those in a calorie deficit, and anyone over 60 years old need significantly more than 0.8 g/kg to maintain or build muscle. Research-based recommendations for active people range from 1.4 to 2.2 g/kg depending on training volume and goal.
Protein provides 4 kilocalories per gram, so your daily protein target also tells you how many of your calories will come from protein. For a person eating 2,000 calories per day with a 150-gram protein target, protein accounts for 600 calories or 30% of total intake, which is a common range in physique-oriented nutrition plans. This calculator shows both the gram target and the calorie equivalent so you can align your protein with your overall macro plan.
📐 Formula
P = wkg × r
P = daily protein intake in grams
wkg = body weight in kilograms
r = protein rate in g/kg, based on goal and activity level (see table below)
Protein calories = P × 4 (protein provides 4 kcal per gram)
Per-meal target = Daily total ÷ number of meals
Reference rates used in this calculator (g/kg body weight), based on ISSN and ACSM guidelines:
| Goal | Sedentary | Light | Moderate | Active | Very Active |
|---|---|---|---|---|---|
| Maintain weight | 0.8 | 1.0 | 1.2 | 1.4 | 1.6 |
| Lose fat | 1.0 | 1.2 | 1.4 | 1.6 | 1.8 |
| Build muscle | 1.2 | 1.4 | 1.6 | 1.8 | 2.0 |
| Athletic performance | 1.4 | 1.6 | 1.8 | 2.0 | 2.2 |
📖 How to Use This Calculator
Steps
1
Enter your body weight. Type your current weight and select kilograms or pounds. The calculator converts to kg internally using the standard 1 lb = 0.4536 kg conversion.
2
Select your goal and activity level. Choose from maintain weight, lose fat, build muscle, or athletic performance. Then select your typical weekly activity level. These two inputs determine your g/kg multiplier from the ISSN reference table.
3
Read your daily protein range. The results show your recommended daily protein in grams, the minimum-to-maximum range, and the calorie contribution. Use the recommended value as your daily target.
4
Switch to Meal Distribution for per-meal targets. Enter your daily protein target and the number of meals you eat per day. The calculator shows how many grams per meal and offers a timing tip based on your meal frequency.
💡 Example Calculations
Example 1 - 80 kg Man Building Muscle, Moderately Active
An 80 kg male trains 4 times per week and wants to maximize muscle gain. What is his daily protein target?
1
Goal: build muscle. Activity: moderate (3-5 days/week). Rate from table: 1.6 g/kg.
2
Recommended daily protein = 80 kg x 1.6 = 128 grams. Range: 80 x 1.4 = 112 g (min) to 80 x 1.8 = 144 g (max).
3
Protein calories = 128 g x 4 kcal/g = 512 kcal from protein per day. On a 2,400 kcal diet, that is 21.3% of calories from protein.
Daily protein = 112 to 144 g, recommended 128 g
Try this example →Example 2 - 65 kg Woman Losing Fat, Very Active
A 65 kg female trains 6 days per week and is in a calorie deficit. How much protein does she need to preserve muscle?
1
Goal: lose fat. Activity: very active (6-7 days/week). Rate: 1.6 g/kg.
2
Recommended protein = 65 x 1.6 = 104 g/day. Range: 65 x 1.4 = 91 g (min) to 65 x 1.8 = 117 g (max).
3
Protein calories = 104 x 4 = 416 kcal. On a 1,600 kcal deficit diet, protein provides 26% of total intake, well within the healthy range of 20-35%.
Daily protein = 91 to 117 g, recommended 104 g
Try this example →Example 3 - Distributing 160 g of Protein Across 4 Meals
A 90 kg athlete needs 160 g of protein per day and eats 4 meals. How much protein per meal?
1
Daily target = 160 g. Number of meals = 4.
2
Protein per meal = 160 / 4 = 40 g. Calories from protein per meal = 40 x 4 = 160 kcal.
3
Real-food equivalents for 40 g protein: 170 g chicken breast (35 g), 200 g Greek yogurt (17 g) plus 2 eggs (12 g), 2 scoops whey protein (48 g), or 200 g canned tuna (44 g).
Per meal = 40 g protein (160 kcal from protein)
Try this example →❓ Frequently Asked Questions
How much protein do I need per day to build muscle?
For muscle gain, research supports 1.6 to 2.2 g per kg of body weight per day (0.73 to 1.0 g/lb). A 75 kg person needs approximately 120 to 165 grams daily. The ISSN recommends 1.4 to 2.0 g/kg as the optimal range for athletes. More than 2.2 g/kg provides no additional muscle-building benefit for most people and just adds unnecessary calories.
How much protein per day do I need to lose weight?
For fat loss, a higher intake of 1.6 to 2.4 g/kg helps preserve muscle in a calorie deficit and increases satiety. A 70 kg person in a cutting phase needs approximately 112 to 168 grams per day. Higher protein during a deficit consistently outperforms lower protein for body composition outcomes in clinical trials, particularly for preserving lean mass while reducing body fat.
Is the 1 gram per pound of body weight rule accurate?
The 1 g/lb rule (2.2 g/kg) is a conservative bodybuilding guideline that exceeds what research shows as necessary. Most people maximize muscle protein synthesis at 1.6 to 2.0 g/kg (0.73 to 0.91 g/lb). The 1 g/lb target is not harmful and acts as a useful buffer for plant-based dieters whose protein quality is lower, but it is not required for muscle growth in omnivores.
What are the best high-protein foods for hitting a daily target?
Top high-protein foods per 100 g: chicken breast (31 g), tuna (30 g), turkey breast (29 g), cottage cheese (11 g per 100 g but typically eaten in 200 g servings for 22 g), Greek yogurt (10 g, consumed in 200 g portions for 20 g), eggs (13 g per 100 g, about 6 g per large egg), beef (26 g), salmon (25 g), and whey protein powder (70 to 90 g per 100 g). Combining 2 to 3 animal protein sources daily makes hitting 150 to 200 g per day straightforward.
How much protein can the body absorb per meal?
The body can absorb all protein consumed, but the rate at which it stimulates muscle protein synthesis plateaus at approximately 20 to 40 g of high-quality protein per meal for most people. Protein above this amount at a single sitting is not wasted but is oxidized for energy or converted to other compounds rather than going to muscle building. This is why spreading protein across 3 to 5 meals is more effective than eating one large protein meal.
Do older adults need more protein than younger people?
Yes. Adults over 60 are recommended to consume 1.0 to 1.2 g/kg at maintenance and up to 1.6 g/kg if active, compared to 0.8 g/kg for younger sedentary adults. This is because older adults develop anabolic resistance, meaning the muscle-building signal from the same amount of protein is weaker than in younger people. Meeting higher protein targets consistently helps prevent sarcopenia (age-related muscle loss), which affects mobility and independence.
Is too much protein bad for your kidneys?
High protein intake is safe for people with healthy kidneys. A comprehensive 2022 review found no evidence that protein intakes up to 2.2 g/kg harm kidney function in healthy individuals. People with pre-existing kidney disease should follow medical guidance, as protein restriction may be recommended in those cases. For healthy adults, including athletes eating 2 to 3 g/kg, no kidney damage has been observed in long-term studies.
Should I eat protein before or after a workout?
Total daily protein matters more than timing for most people. The post-workout anabolic window is real but wider than originally thought, roughly 4 to 6 hours around a training session, not a narrow 30-minute window. Having a protein-containing meal within 2 hours before or after training is sufficient. If you train fasted, consuming 20 to 40 g of protein within 60 minutes post-workout is beneficial. Meeting your daily total is the primary priority.
How do vegetarians and vegans get enough protein?
Vegetarians with access to dairy and eggs can hit protein targets easily: eggs, Greek yogurt, cottage cheese, and whey protein are complete proteins. Vegans should combine plant proteins for complete amino acid profiles (rice plus lentils, corn plus beans, soy, quinoa) and target the upper end of the recommended range (1.8 to 2.2 g/kg) to compensate for lower leucine content and digestibility of plant protein versus animal protein. Pea protein, soy protein, and hemp protein are the highest-quality vegan protein supplements.
How many grams of protein does a 2-scoop protein shake provide?
Most whey protein powder servings (typically 30 to 35 g per scoop) provide 20 to 25 g of protein per scoop. Two scoops provide 40 to 50 g of protein. Protein content varies by brand and type: whey concentrate averages 24 g per scoop, whey isolate provides 25 to 28 g, and casein averages 24 g. Always check the nutrition label for the exact protein content per serving of your specific product.
Does cooking reduce the protein content of food?
Cooking does not destroy protein. Heat denatures (unfolds) protein molecules, which changes texture but does not eliminate the amino acids. Protein content is measured per cooked or raw weight depending on the food database. Chicken breast, for example, loses about 25% of its weight when cooked because water evaporates, so 100 g of cooked chicken contains more protein per gram than 100 g of raw chicken. Most online nutrition databases list values for cooked weights, so use cooked weights when tracking.
How much protein do I need if I am sedentary and not trying to lose or gain?
For a sedentary adult maintaining weight, the DRI (Dietary Reference Intake) recommends 0.8 g/kg per day as the minimum. For a 70 kg sedentary person, that is 56 grams per day. However, most nutrition researchers recommend 1.0 to 1.2 g/kg even for sedentary adults to support immune function, enzyme production, and tissue maintenance above the minimum. The 0.8 g/kg RDA is set at the level needed to prevent deficiency, not at an optimal level for health.