Protein Calculator for Weight Loss & Muscle Gain

Enter your age, weight, and activity level, and the Legion Protein Calculator will tell you exactly how much protein you need to eat per day to lose weight, build muscle, or maintain your physique.

What Is Protein? 

Protein is a macronutrient essential for building, repairing, and maintaining tissues in your body, including muscles, skin, and organs.

It’s made up of amino acids—the “building blocks” your body uses to grow and repair cells. 

Protein also plays a key role in various bodily functions, such as producing hormones, supporting immune function, and providing energy when needed.

There are 20 amino acids that comprise the protein in your body. Your body can produce 11 amino acids on its own, but it must get the remaining 9 from your diet, which is why eating protein is vital for life.

How Much Protein Do I Need? Calculator Results Explained

The current Recommended Dietary Allowance (RDA) for protein in the US is 0.8 grams per kilogram of body weight per day, or about 0.36 grams per pound of body weight per day. 

That said, a large body of evidence shows that this is inadequate for maintaining or building muscle mass, optimizing fat loss, and maximizing your health and performance, especially if you’re active. 

What’s more, recent evidence suggests that even the current RDA may be insufficient for supporting health, and that it should be adjusted upward to 1.0 g/kg/day, or about 0.45 g/lb/day.

For example, in a study published in the British Journal of Nutrition, healthy, sedentary adults ate 40% more calories than they needed to maintain their weight and three different amounts of protein: 0.7 g/kg (a tad less than the RDA), 1.8 g/kg, and 3.0 g/kg. 

The people who consumed the RDA of protein lost muscle mass despite being in a calorie surplus, whereas the people who ate more protein gained muscle. 

That said, eating as much protein as possible isn’t better. While studies show it’s safe to eat 1.5-to-2+ grams of protein per pound of body weight per day, this isn’t necessary to optimize muscle growth, fat loss, or health.

RELATED: Is High-Protein Dieting Bad for Your Kidneys?

In other words, eating a very high-protein diet (more than 1 g/lb/day) isn’t “bad,” but research shows it probably isn’t any better than eating a moderate amount of protein (0.8-to-1 g/lb/day). 

Many fitness folks deliberately eat a little more protein than research shows is necessary as a way to ensure they aren’t missing out on any of its benefits. For example, instead of eating 0.8 g/lb/day, which for a 200-pound man would be 160 grams of protein, they choose to eat 1 g/lb/day, which is 200 grams. 

This only adds 160 calories to their daily food intake, so it doesn’t meaningfully reduce how much carbohydrate and fat they can eat per day.

What you don’t want to do is eat so much additional protein that you have to significantly reduce your carbohydrate and fat intake, as this can negatively impact your workout performance, recovery, and hormonal health. 

Our protein calculator uses this up-to-date science to put you in the Goldilocks zone for protein intake—enough to maximize fat loss, muscle gain, and satiety, while still leaving ample room for carbs and fat in your diet. 

The Benefits of Using the Legion Protein Calculator for Weight Loss

If you’re trying to lose fat while minimizing muscle loss, research shows you should eat between 0.5-to-1 grams of protein per pound of body weight per day.

If you’re lifting weights or doing several hard or prolonged workouts per week, such as running, martial arts, or team sports, then you’ll want to aim for the upper end of this range—around 0.8-to-1 grams of protein per pound of body weight per day.

If you’re physically active, but aren’t lifting weights or doing vigorous or prolonged workouts, and aren’t trying to lose weight, then you can get by with less protein—around 0.5-to-0.7 grams of protein per pound of body weight per day. 

And if you’re sedentary (which isn’t ideal if you want to take care of your health), research shows you can eat as little as 0.4 grams of protein per pound of body weight per day without losing muscle. 

Aside from preserving muscle mass, another reason to eat more protein than the RDA is that it improves satiety, which makes it easier to maintain a calorie deficit. 

Protein also “costs” more calories to digest than carbohydrate and fat, and so eating more protein slightly boosts metabolic rate (though the effect isn’t enough to have a meaningful impact on weight loss).

Some protein calculators recommend much higher intakes than this—all the way up to 1.5 g/lb per day or more. These suggestions are based on outdated research (or just good ol’ fashioned broscience), which overestimated the amount of protein you need to prevent muscle loss while dieting. 

Newer studies have shown that these recommendations are excessive and can make dieting more challenging by reducing the calories available for carbs and fats.

While it’s fine to eat slightly more protein than necessary “just in case,” eating too much can make dieting more difficult and unpleasant by limiting your food options. 

If you eat so much protein that you have to severely restrict your carbohydrate and fat intake, this can also hurt workout performance, recovery, and hormonal health.

Thus, when trying to lose weight, you want to eat enough protein to preserve muscle and stay satisfied between meals, but not much more than this. 

Protein is just one piece of the fat loss puzzle, though. You also need to eat the right number of calories and the right balance of carbs and fat. For personalized advice on calories and macros, check out our macronutrient calculator:

The Legion Macronutrient Calculator

The Benefits of Using the Legion Protein Calculator for Muscle Gain

If your goal is to gain muscle, it’s essential that you eat a high-protein diet. 

Research shows that increasing protein intake beyond the RDA significantly increases muscle growth, especially when combined with strength training.

For example, a meta-analysis of 49 studies found that consuming 0.7-to-0.8 grams of protein per pound of body weight per day optimizes muscle gain for weightlifters. 

Your body’s ability to use protein for muscle building hits a ceiling around this point, though, so eating more doesn’t lead to much if any additional muscle gain. 

That said, your protein needs may be slightly higher depending on factors like your genetics, activity level, training volume, and weightlifting experience, which is why many people trying to gain muscle choose to eat slightly more—typically around 1 gram of protein per pound of body weight per day. 

If you’re unsure about the exact amount of protein to build muscle, our calculator can give you personalized recommendations based on the latest research.

Of course, protein alone won’t get you the results you’re after. You need to follow a well-rounded diet with the right balance of carbs, fat, and calories combined with an effective strength training plan to optimize muscle growth.

Take the Legion Diet Quiz and Training Quiz to get a custom-made diet and training plan in less than 60 seconds. 

How to Use the Legion Protein Calculator for Seniors

Research shows that people over 60 years old should eat a minimum of 0.5-to-0.8 grams of protein per pound of body weight per day, depending on their activity level. 

The lower end is usually sufficient for preventing muscle loss in sedentary people, while the higher end is helpful for maximizing muscle gain and maintenance for older folks who lift weights.

As we age, maintaining muscle mass and strength becomes increasingly important—it helps us stay mobile, lowers the risk of falls and fractures, and reduces the likelihood of illness and frailty.

Research consistently shows that protein plays a crucial role in this process.

For instance, a meta-analysis of 7 studies found that older adults who consumed more than 0.5 grams of protein per pound of body weight per day maintained better mobility, while those eating less experienced greater muscle loss and frailty.

Another systematic review published in the Journal of the American College of Nutrition showed that seniors who ate more protein than the RDA (0.4 g/lb/day) significantly reduced their risk of hip fractures, which highlights the role of protein in bone health.

Higher protein intakes also reduce the risk of chronic diseases.

A study published in The American Journal of Clinical Nutrition tracked 50,000 people over 30 years and found that older folks who consumed up to 23% of their daily calories from protein were less likely to develop chronic diseases like heart disease, diabetes, or cancer. They also maintained better cognitive and physical function.

For every 3% increase in total protein intake, the study showed a 5% relative improvement in the likelihood of aging without chronic illness.

Use our protein per day calculator to easily find your optimal daily protein intake to help you stay strong and vital as you age.

How to Meet Your Daily Protein Goal

Here are three practical tips to consistently hit your daily protein target: 

• Eat 30-to-40 grams of protein per meal. The best way to meet your daily protein needs is to make sure you eat 3-to-4 meals with 30-to-40 grams of protein in each. If you do this, it’s hard not to get close to your daily protein target every day. 
• Supplement with protein powder, bars, and cookies. When you’re on-the-go or just don’t feel like preparing or eating normal food, protein powder, bars, and cookies are a convenient and tasty way to boost your protein intake.
• Snack on high-protein foods: Keep high-protein snacks on hand for in-between meals. Skyr, Greek yogurt, cottage cheese, jerky, meat sticks, hard-boiled eggs, and edamame are all good options that require minimal prep.

What Are the Best High-Protein Foods?

Below are some of the best foods for preparing high-protein meals.

• Poultry: Chicken breast, turkey breast, ground turkey, chicken thighs.
• Red Meat: Ground beef (90% lean or higher), top sirloin steak, pork tenderloin, pork chops, bison, lamb.
• Fish: Tuna, salmon, cod, mackerel, halibut, sardines.
• Shellfish: Shrimp, crab, lobster, scallops, clams, mussels.
• Eggs: Whole eggs and egg whites.
• Low-Fat Dairy: Low-fat milk, Greek yogurt, Skyr, cottage cheese, low-fat cheese (mozzarella, Swiss), kefir.
• Legumes: Black beans, lentils (red, green, or brown), chickpeas, kidney beans, pinto beans, edamame, peas.
• Whole Grains: Brown rice, quinoa, millet, farro, barley, buckwheat, bulgur.
• Nuts and Seeds: Almonds, cashews, pistachios, walnuts, hemp seeds, chia seeds, flaxseeds, sunflower seeds, pumpkin seeds, sesame seeds.
• Vegetables: Broccoli, cauliflower, Brussels sprouts, asparagus, spinach, kale, green peas, edamame.

How Much Protein Can Your Body Absorb In a Single Meal? 

Your body can absorb and effectively use 100 or more grams of protein in a single meal.

That said, most research shows that you’ll maximize the muscle-building benefits of protein if you divide your daily protein intake across 3-to-4 meals per day, at least 3 hours apart, with at least 20-to-30 grams of protein in each meal. 

This is because eating protein increases muscle protein synthesis (the creation of new muscle proteins), and reduces muscle protein breakdown (the breakdown of muscle proteins). 

This effect only lasts for several hours, though, which is why it’s ideal to consume several protein-rich meals throughout the day, which boosts protein synthesis and suppresses protein breakdown for as long as possible.