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
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
💡 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?
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?
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?
❓ Frequently Asked Questions
🔗 Related Calculators
How much protein do I need per day to build muscle?
For muscle gain, most research supports 1.6 to 2.2 g of protein per kg of body weight per day (0.73 to 1.0 g/lb). A 75 kg person looking to build muscle needs approximately 120 to 165 grams per day. The ISSN (International Society of Sports Nutrition) 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.
How much protein do I need per day to lose weight?
For fat loss, a higher protein intake of 1.6 to 2.4 g/kg body weight helps preserve muscle mass in a calorie deficit. Higher protein also increases satiety, which makes calorie restriction easier to sustain. A 70 kg person cutting calories needs approximately 112 to 168 grams of protein per day. This is meaningfully higher than the 0.8 g/kg RDA, which is a minimum for sedentary adults, not an optimal target for body recomposition.
Is 1 gram of protein per pound of body weight a good rule?
The 1 g/lb rule (approximately 2.2 g/kg) is a conservative upper guideline used in bodybuilding communities. Research shows that most people reach maximum muscle protein synthesis at 1.6 to 2.0 g/kg (0.73 to 0.91 g/lb). The 1 g/lb rule is not harmful and provides a buffer for plant-based dieters or those who under-report intake, but it is not necessary for most people. Going above 2.2 g/kg has no additional benefit and is expensive in calories.
How much protein do I need if I don't exercise?
The RDA for sedentary adults is 0.8 g of protein per kg of body weight per day, which is the minimum needed to prevent deficiency. For a 70 kg sedentary adult, that is 56 grams per day. However, many nutrition scientists argue that 1.0 to 1.2 g/kg is more appropriate for general health and to slow age-related muscle loss. The 0.8 g/kg RDA represents the floor, not the optimum.
Does protein intake need to change as you get older?
Yes. Adults over 60 typically need more protein than younger adults to maintain muscle mass because older muscles are less responsive to protein and the anabolic signal of each meal. Research suggests 1.2 to 1.6 g/kg for older adults, with some studies recommending up to 2.0 g/kg for those with existing muscle loss (sarcopenia). Spreading intake across meals is especially important since older adults need more leucine per meal to trigger muscle protein synthesis.
What foods are highest in protein per 100g?
The highest-protein foods include: parmesan cheese (38 g/100g), whey protein powder (75-90 g/100g), chicken breast cooked (31 g/100g), tuna canned in water (26 g/100g), lean beef (26 g/100g), eggs (13 g/100g), Greek yoghurt (10 g/100g), lentils cooked (9 g/100g), and tofu (8 g/100g). Animal proteins are generally more complete and concentrated than plant proteins. Use these figures to plan how to reach your daily gram target from whole foods.
Can eating too much protein be harmful?
For healthy adults, protein intakes up to 2.5 g/kg body weight per day appear safe based on current evidence. Very high intakes (above 3.5 g/kg) may strain kidney function over the long term, though this risk is primarily for people with pre-existing kidney disease. High protein diets can also crowd out fibre and micronutrients if not balanced. For most people staying within 1.6 to 2.2 g/kg, there is no meaningful health risk from protein intake alone.
How does protein help with weight loss?
Protein supports fat loss through three main mechanisms. First, it has the highest thermic effect of any macronutrient: digesting protein burns 20 to 30% of its calories, compared to 5 to 10% for carbs and 0 to 3% for fat. Second, protein is the most satiating macronutrient, reducing hunger hormones and increasing fullness hormones. Third, adequate protein during a calorie deficit preserves lean muscle mass so that weight lost is predominantly fat, not muscle.