Free protein calculator

How to use the protein calculator

This protein calculator turns your body weight and goal into a daily protein range, grams per pound, grams per kilogram and a per-meal split.

1. Pick your units. Choose lb, kg or stone. If you pick stone, a second box appears for the extra pounds, so 11 st 4 lb is 11 and 4.
2. Enter your body weight. Use your current weight on a normal morning.
3. Choose a goal. General health, active or building muscle, losing fat while keeping muscle, or age 65 or older.
4. Choose your activity. This matters most for the general health and age 65+ goals.
5. Add body fat % if you are cutting. It is optional. With it, the fat-loss range is based on lean mass rather than total weight.

The result updates as you type. Below the daily range you get grams per pound, grams per kilogram and grams per meal for three, four or five meals. The link in your browser bar holds your inputs, so you can bookmark or share it.

Every range comes from a published guideline or review, named under the result. This page is a research compilation. Nothing here was tested on people by Home Gym Journal.

How much protein do I need a day?

For a healthy adult who does not train, the floor is 0.8 g of protein per kg of body weight a day. That is about 0.36 g per pound. People who exercise, want to build muscle, are dieting or are over 65 need more, usually between 1.0 and 2.0 g per kg.

The 0.8 g per kg figure is the Recommended Dietary Allowance (RDA). The RDA is the daily amount that meets the needs of nearly all healthy people. Harvard’s Nutrition Source notes that the National Academy of Medicine set it as a minimum.

The RDA was not built for people trying to add muscle. The International Society of Sports Nutrition (ISSN) position stand on protein and exercise says that 1.4 to 2.0 g per kg a day is enough for most exercising people to build and keep muscle.

What the calculator uses for each goal

Each goal in this protein requirements calculator maps to one published range.

Goal in the calculator	Range used	g per lb	Source
General health	0.8 g/kg, a minimum	0.36	RDA, National Academy of Medicine
Active or building muscle	1.4–2.0 g/kg	0.64–0.91	ISSN position stand, 2017
Losing fat, body fat % known	2.3–3.1 g/kg of lean mass	1.04–1.41 per lb of lean mass	Helms et al., 2014
Losing fat, body fat % blank	1.4–2.0 g/kg	0.64–0.91	ISSN position stand, 2017
Age 65+, little exercise	1.0–1.2 g/kg	0.45–0.54	PROT-AGE, 2013
Age 65+, active	1.2 g/kg or more	0.54 or more	PROT-AGE, 2013

Where a guideline gives only a minimum, the calculator shows your number with a plus sign, such as “65+ g a day”. That means “at least this much”, not a cap.

The protein formula, with a worked example

Daily protein in grams equals body weight in kg times a grams-per-kg factor. To use pounds, divide your weight by 2.2046 first.

Daily protein (g) = body weight (kg) × factor (g/kg)

Per meal (g) = daily protein ÷ number of meals

Worked example for a 180 lb person who lifts four days a week:

• 180 lb ÷ 2.2046 = 81.6 kg
• Low end: 81.6 × 1.4 = 114 g a day
• High end: 81.6 × 2.0 = 163 g a day
• Middle point that research flags: 81.6 × 1.6 = 131 g a day
• Four meals: 114 ÷ 4 to 163 ÷ 4 = about 29 to 41 g per meal

The middle point matters. A 2018 meta-analysis by Morton and colleagues pooled 49 trials with 1,863 people who did resistance training. It found that protein intakes above about 1.62 g per kg a day gave no further gains in fat-free mass. So 1.6 g per kg is a sensible target for most lifters, and the rest of the ISSN range gives you room.

Worked example for fat loss

A 200 lb person with 30% body fat wants to lose fat and keep muscle.

• 200 lb ÷ 2.2046 = 90.7 kg
• Lean mass: 90.7 × (1 − 0.30) = 63.5 kg
• Low end: 63.5 × 2.3 = 146 g a day
• High end: 63.5 × 3.1 = 197 g a day

The Helms review found protein needs for lean lifters on a diet are likely 2.3 to 3.1 g per kg of fat-free mass, “scaled upwards with severity of caloric restriction and leanness”. The review looked at lean, trained lifters (men at or under 23% body fat, women at or under 35%). If you are newer to training or carry more fat, the low end is plenty. If you do not know your body fat, the calculator falls back to the ISSN range of 1.4 to 2.0 g per kg of body weight.

Protein by body weight: chart in pounds and kilograms

These tables give daily grams for common weights, rounded to the nearest gram. The 1.6 g/kg column is the point where extra gains leveled off in the Morton meta-analysis.

Protein chart in pounds

Body weight	RDA 0.8 g/kg	Age 65+ active, 1.2 g/kg	Training, 1.4–2.0 g/kg	Target 1.6 g/kg
120 lb	44 g	65 g	76–109 g	87 g
140 lb	51 g	76 g	89–127 g	102 g
160 lb	58 g	87 g	102–145 g	116 g
180 lb	65 g	98 g	114–163 g	131 g
200 lb	73 g	109 g	127–181 g	145 g
220 lb	80 g	120 g	140–200 g	160 g
250 lb	91 g	136 g	159–227 g	181 g

Protein calculator in kg

Body weight	RDA 0.8 g/kg	Age 65+ active, 1.2 g/kg	Training, 1.4–2.0 g/kg	Target 1.6 g/kg
50 kg	40 g	60 g	70–100 g	80 g
60 kg	48 g	72 g	84–120 g	96 g
70 kg	56 g	84 g	98–140 g	112 g
80 kg	64 g	96 g	112–160 g	128 g
90 kg	72 g	108 g	126–180 g	144 g
100 kg	80 g	120 g	140–200 g	160 g
110 kg	88 g	132 g	154–220 g	176 g

At high body weights, total-weight numbers climb fast. A 250 lb person does not usually need 227 g a day. If much of your weight is fat, base your target on a lower weight or use the lean-mass option, and talk to a dietitian if you are unsure.

Grams of protein per pound of body weight

To convert a grams-per-kg guideline to grams per pound, divide by 2.2046. So 1.6 g per kg is about 0.73 g per pound, and 0.8 g per kg is about 0.36 g per pound.

The old gym rule of “1 gram per pound” works out to about 2.2 g per kg. It sits just above the ISSN range. It is more than most lifters need to build muscle, though it overlaps with the higher intakes the ISSN mentions for lean lifters who are dieting.

How much protein per meal?

Aim for about 0.25 to 0.4 g of protein per kg of body weight at each meal, spread over three to five meals. For most adults that is 20 to 40 g a meal.

The ISSN position stand says a general per-serving guide is 0.25 g of high-quality protein per kg of body weight, or an absolute dose of 20 to 40 g. It also says those doses should be spread evenly, every 3 to 4 hours, across the day. Each dose should contain 700 to 3,000 mg of leucine, an amino acid that helps switch on muscle building.

A 2018 review by Schoenfeld and Aragon took a closer look at the “20 to 25 g per meal” idea. It concluded that the idea came from studies of fast-digesting protein eaten on its own. Mixed meals digest more slowly. Their suggestion: eat 0.4 g per kg per meal across at least four meals to reach at least 1.6 g per kg a day. If you aim for the upper end of 2.2 g per kg, that is up to 0.55 g per kg per meal.

Protein per meal by body weight

Body weight	ISSN guide, 0.25 g/kg	Schoenfeld and Aragon, 0.4 g/kg	Upper end, 0.55 g/kg
140 lb (64 kg)	16 g	25 g	35 g
160 lb (73 kg)	18 g	29 g	40 g
180 lb (82 kg)	20 g	33 g	45 g
200 lb (91 kg)	23 g	36 g	50 g
220 lb (100 kg)	25 g	40 g	55 g

How much protein can your body absorb at once?

Your gut absorbs almost all the protein you eat, so “absorb” is the wrong word. The useful question is how much one meal can put toward muscle. Schoenfeld and Aragon found that doses above 20 g raise the share of amino acids burned for energy, but not all of the extra is wasted. So a 50 g meal is not a problem.

Does timing around workouts matter?

Less than you might think. The ISSN says timing is mostly personal preference: protein before or after training both help, and a workout’s effect lasts at least 24 hours. Your daily total matters most.

Protein calculator for weight loss

When you cut calories, eat toward the top of your range. More protein helps you keep muscle while you lose fat. The ISSN says intakes of 2.3 to 3.1 g per kg may be needed to keep the most lean mass in trained people who are eating below maintenance.

Helms and colleagues reviewed six studies of lean, trained lifters on a diet. The authors set their range per kg of fat-free mass, not total weight. That is why the protein calculator for weight loss asks for body fat percentage.

Practical steps for a fat-loss phase:

• Keep lifting. Protein supports muscle, but the training signal is what tells your body to keep it.
• Pick lean sources such as chicken breast, tuna, Greek yogurt and egg whites, which pack protein into fewer calories.

Protein calculator to gain muscle

To gain muscle, most people do well at 1.6 g per kg a day, inside the ISSN range of 1.4 to 2.0 g per kg. Pair it with a steady strength program and enough total calories.

The Morton meta-analysis is the key study here. Across 49 trials, adding protein increased one-rep-max strength by an average of 2.49 kg and fat-free mass by 0.30 kg over programs lasting at least six weeks. The boost from protein was larger in people who already trained and smaller as age went up. The plateau near 1.62 g per kg is an average across studies, not a rule for every person. That is why the protein calculator to gain muscle shows the whole ISSN range, not just one number.

Protein does not build muscle on its own. You need progressive overload: adding weight, reps or sets over time. You can track that with our one rep max calculator, and check how much lean mass you are carrying with the FFMI calculator. Effort matters too. The RPE calculator helps you judge how hard each set really was.

Protein calculator for women

Women need the same protein per kilogram as men. The guidelines on this page, the RDA, the ISSN range and the PROT-AGE advice, all set targets in grams per kg of body weight with one number for adults, not separate numbers by sex. A woman’s daily total often comes out lower only because she weighs less.

So a 140 lb woman who lifts gets the same 89 to 127 g range as a 140 lb man.

Pregnancy and breastfeeding

Pregnancy raises protein needs. A National Academies workshop summary lists the current US figures: an RDA of 1.1 g per kg a day in pregnancy and 1.3 g per kg a day while breastfeeding. It also reports newer research estimating needs of about 1.2 g per kg in early pregnancy and 1.52 g per kg in late pregnancy. These are research estimates, not official targets. The calculator does not include a pregnancy setting. If you are pregnant or breastfeeding, follow your doctor’s or midwife’s advice.

How much protein do older adults need?

Adults over 65 need more protein per kilogram than younger adults. The PROT-AGE study group recommends at least 1.0 to 1.2 g per kg a day, and at least 1.2 g per kg for those who exercise or are otherwise active.

The group explains that the body responds less to protein with age. Illness also raises needs. Most older adults with a short-term or long-term illness need 1.2 to 1.5 g per kg a day, according to the paper.

Worked example: a 150 lb (68 kg) 70-year-old who walks and lifts light dumbbells twice a week.

• 68 × 1.2 = 82 g a day, as a minimum
• Split over three meals: about 27 g per meal

Resistance training at home can be simple for older adults. A pair of adjustable dumbbells or a single kettlebell covers most of the basics. Start light and get a doctor’s OK if you have heart, joint or balance problems.

Protein in food: grams per serving

You can reach most protein targets with ordinary food. The table below uses USDA FoodData Central values per 100 g, scaled to a common serving by weight. Brands and cooking methods vary, so check the label on what you buy.

Food (USDA FoodData Central entry)	Protein per 100 g	Serving	Protein per serving
Chicken breast, meat only, roasted	31.0 g	85 g (3 oz)	26 g
Ground beef 90% lean, patty, broiled	26.1 g	85 g (3 oz)	22 g
Light tuna, canned in water, drained	25.5 g	85 g (3 oz)	22 g
Tofu, firm, made with calcium sulfate	17.3 g	100 g	17 g
Egg, whole, hard-boiled	12.6 g	50 g (1 large egg)	6 g
Cottage cheese, lowfat 2%	10.4 g	113 g (about ½ cup)	12 g
Greek yogurt, plain, nonfat	10.2 g	170 g (6 oz)	17 g
Lentils, boiled	9.0 g	198 g (about 1 cup)	18 g
Black beans, boiled	8.9 g	172 g (about 1 cup)	15 g
Milk, 2%	3.3 g	244 g (1 cup)	8 g

A sample day near 131 g: Greek yogurt and two eggs (29 g), a tuna sandwich (22 g plus bread), milk and cottage cheese (20 g), chicken breast with lentils (44 g), and a shake to close the gap. The ISSN advises focusing on whole foods that contain all the essential amino acids. If you eat plant-based, mix sources through the day.

Where protein powder fits

Protein powder is a convenience, not a must. The ISSN says active people can get all the protein they need from whole foods. It also says supplements are a practical way to get enough good-quality protein without many extra calories.

Powder helps most when:

• Your target is high and your appetite is small.
• You are in a calorie deficit and want protein without much fat or carbohydrate.
• You train early or late and a full meal is not practical.

The ISSN points to proteins that digest fast and carry plenty of essential amino acids and leucine as the most effective for muscle building. The ISSN also reports that 30 to 40 g of casein before bed raised overnight muscle building.

How to read and act on your result

Treat the number as a range, not a line to hit to the gram. If the calculator says 114 to 163 g, pick one round number, such as 130 g, and aim for it most days.

Steps that make the target stick:

1. Set a per-meal number. Use the table under the result. Hitting 30 to 40 g at each of four meals is easier than chasing a daily total at 9 p.m.
2. Track for one week. A food app will show whether you are near your range.
3. Recheck when your weight changes. A 10 lb change shifts the range by about 6 to 9 g at the training end.

Accuracy limits: who this does not fit

The calculator gives estimates for healthy adults. It multiplies your weight by factors from group studies, so your true need could sit a little above or below the range.

It does not fit well for:

• People with kidney disease. The PROT-AGE paper singles out people with severe kidney disease (eGFR below 30) who are not on dialysis: they may need to limit protein. Anyone with kidney problems should get a target from their doctor or a renal dietitian.
• Pregnancy and breastfeeding. See the section above; the needs differ and change by trimester.
• Children and teens. These guidelines are for adults.
• Very high body fat. Total-weight factors overstate needs. Use the lean-mass option or a lower reference weight.
• Elite endurance athletes. The ISSN says endurance athletes should put carbohydrate first. Their needs are best set with a sports dietitian.
• People recovering from surgery or illness. Needs can rise, but set them with your care team.

Common protein mistakes

Most mistakes come from using the wrong number or bunching all the protein into one meal.

• Treating the RDA as a target for lifters. It is a minimum for healthy adults. Lifters need more.
• Going far past what you need. Above about 1.6 g per kg, gains in muscle leveled off in the Morton meta-analysis. Extra protein beyond your range mostly adds calories and cost.
• Using goal weight when you have a lot to lose. Use current weight with body fat %, or ask a dietitian.
• Forgetting the training. Protein supports muscle growth; lifting drives it.

Metric and UK units: kg and stone

The calculator takes lb, kg or stone. One stone is 14 lb, or 6.35 kg. If you weigh 12 st 6 lb, choose stone, enter 12 in the first box and 6 in the second.

Body weight	Kilograms	RDA 0.8 g/kg	Training, 1.4–2.0 g/kg	Target 1.6 g/kg
8 st	51 kg	41 g	71–102 g	81 g
10 st	64 kg	51 g	89–127 g	102 g
12 st	76 kg	61 g	107–152 g	122 g
14 st	89 kg	71 g	124–178 g	142 g
16 st	102 kg	81 g	142–203 g	163 g

All the research on this page works in grams per kg, so metric users can skip the conversion step.

Protein and your home gym

Protein only pays off if you train. A basic home setup is enough to give your body a reason to build and keep muscle. Our guide on how to set up a home gym covers space, flooring and the order to buy things. The best home gym equipment roundup lists what gives the most exercises per dollar.

A set of adjustable dumbbells and a bench cover presses, rows, squats and lunges. If your weight or goal changes, run the protein intake calculator again.

Safety note

This page shares ranges from published guidelines for healthy adults. It is not medical or dietary advice. If you have kidney or liver disease, diabetes, a history of disordered eating, or you are pregnant, breastfeeding or on medication, ask a doctor or registered dietitian before you change how much protein you eat. When you start lifting, begin with light weights and good form, and stop if you feel chest pain, dizziness or sharp joint pain.