Protein calculator: daily protein intake per kg
Protein needs are counted in grams per kilogram of body weight, and they depend on whether you train. If you train regularly, the calculator stays inside the ISSN 2017 range for people who exercise, 1.4–2.0 g/kg: 1.4 to maintain, 1.8 to lose weight, 1.6 to gain and 2.0 for recomposition. At 70 kg that's 98, 126, 112 and 140 g. Without training the target is lower: 0.83 g/kg to maintain and 1.2 g/kg to lose weight, so 58 and 84 g at the same 70 kg. For food examples, read how much protein women and men need a day.
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Where the number comes from
The formula, a worked example and where it stops working
Why protein matters
How much protein you need a day depends on your weight, your goal and whether you train. The International Society of Sports Nutrition Position Stand, 2017 says 1.4-2.0 g of protein per kg of body weight a day is enough for most people who train, and that in a calorie deficit they may need more to keep their muscle. For an adult who doesn't train, EFSA puts the reference intake at 0.83 g/kg, and for weight loss a review by Leidy and colleagues (2015) suggests 1.2–1.6 g/kg: that much protein helps you keep muscle and keep your appetite in check.
Here is how the calculator works it out. Sedentary counts as not training: 0.83 g/kg to maintain, 1.2 g/kg to lose weight and 1.4 g/kg for gain and recomposition. From light activity, 1-3 workouts a week, it uses 1.4 to maintain, 1.8 to lose weight, 1.6 to gain and 2.0 for recomposition. It never goes below 0.83 or above 2.0 g/kg.
Protein is the main building material of your body: muscle, skin, hair and enzymes are made of it. In a calorie deficit it matters even more: eat too little and you lose muscle along with the fat, which is exactly what you want to hang on to.
How to calculate protein per kg of body weight
There is one formula: weight in kilograms × a factor. The factor depends on your goal and on whether you train; both charts are below. Height, age and activity are also used for one check: protein should not take more than 35% of the day's calories (the top of the IOM acceptable range). That only kicks in rarely, at a very high body weight while cutting. Otherwise all the accuracy sits in the factor and in which weight you plug in.
The factor is not a single point but a place inside a range. For a 65 kg woman who trains, the ends of the ISSN 1.4-2.0 g/kg range are 91 and 130 g a day, and both are workable: it comes down to your goal and how much you train. Without training, the same woman needs 54 g to maintain and 78 g to lose weight.
The calculator uses total body weight, because few people know their body-fat percentage. With a lot of fat, total weight overstates protein, and lean mass — your weight minus fat — is the fairer base. Example: 100 kg at 40% fat is 60 kg of lean mass. Cutting with training, 1.8 × 60 = 108 g instead of 180 g on total weight. You can estimate your body fat from tape measurements in the body fat calculator.
Protein chart if you train: grams a day by weight and goal
Find your weight and goal; where they meet is your daily protein in grams. This is moderate activity, 3-5 workouts a week; with light activity, 1-3 workouts, the factors are the same. The columns are the same goals as in the calculator above.
Recomposition means losing fat while building muscle at close to zero deficit. Its factor is the highest, 2.0 g/kg, the top of the ISSN range, and the calculator never goes above it.
| Weight | Weight loss | Maintenance | Muscle gain | Recomposition |
|---|---|---|---|---|
| 50 kg | 90 g | 70 g | 80 g | 100 g |
| 60 kg | 108 g | 84 g | 96 g | 120 g |
| 70 kg | 126 g | 98 g | 112 g | 140 g |
| 80 kg | 144 g | 112 g | 128 g | 160 g |
| 90 kg | 162 g | 126 g | 144 g | 180 g |
| 100 kg | 180 g | 140 g | 160 g | 200 g |
| 110 kg | 198 g | 154 g | 176 g | 220 g |
Grams of protein a day. Woman, 30, 165 cm, moderate activity. Goal factors are 1.8, 1.4, 1.6 and 2.0 g/kg, capped at 35% of calories. Men get the same grams. The same maths as in the calculator.
Protein chart if you don't train
The calculator treats a sedentary day with no workouts as not training. Where that line sits is our call: the ISSN range comes from people who train, and we apply it from light activity up, so from 1-3 workouts a week.
The numbers here are noticeably lower. To maintain, the EFSA reference intake for all adults is enough; to lose weight, 1.2 g/kg. Building muscle and recomposition don't really happen without training; if you pick those goals anyway, the calculator uses the bottom of the ISSN range, 1.4 g/kg.
| Weight | Weight loss | Maintenance | Muscle gain | Recomposition |
|---|---|---|---|---|
| 50 kg | 60 g | 42 g | 70 g | 70 g |
| 60 kg | 72 g | 50 g | 84 g | 84 g |
| 70 kg | 84 g | 58 g | 98 g | 98 g |
| 80 kg | 96 g | 66 g | 112 g | 112 g |
| 90 kg | 108 g | 75 g | 126 g | 126 g |
| 100 kg | 120 g | 83 g | 140 g | 140 g |
| 110 kg | 132 g | 91 g | 154 g | 154 g |
Grams of protein a day. Woman, 30, 165 cm, sedentary. Factors are 1.2 for weight loss, 0.83 for maintenance, 1.4 for gain and recomposition. Protein never drops below 10% of calories, so lighter men get slightly more grams at maintenance. The same maths as in the calculator.
A worked example with real numbers
A woman of 30, 65 kg, training 3-4 times a week, which is moderate activity, goal fat loss. Her target in the calculator is 1.8 × 65 = 117 g of protein a day. Here is what that looks like as ordinary food, by raw weight:
- 250 g chicken breast — about 56 g of protein (Canadian Nutrient File)
- 200 g of 4.5% cottage cheese — about 22 g (same source)
- two eggs, about 100 g without the shell — about 12 g
- 150 g of cod — about 27 g
- together that is roughly 117 g: four ordinary foods cover the target, no shakes or powders
- if the same woman just holds her weight, the target is 91 g; for muscle gain 104 g; for recomposition 130 g
- without regular training she would need 1.2 × 65 = 78 g while cutting, roughly 170 g of chicken breast less
When the number does not fit
All these targets come from healthy adults. Outside that group, do not take the calculator's number — protein needs are a conversation with a doctor.
- Kidney disease — protein is restricted there, and a doctor sets the target, not a calculator
- Liver disease and metabolic disorders — same
- Pregnancy and breastfeeding — needs are different and not something to size up with an online calculator
- A very high body-fat percentage — work from lean mass, or the number comes out too high
- Under 18 — children and teenagers have their own norms
What to do with the number next
Protein is one of three parts of your diet. How much room that leaves for fat and carbs is what the macro calculator shows: it splits your calories into protein, fat and carbs in grams.
If you are losing weight, work out your calorie target in the calorie deficit calculator first, then check that your protein fits inside it. More on foods and spreading protein across meals in the article on how much protein you need per day.
And log what you eat for two weeks: until you count, most people think they eat more protein than they do.
How we calculate
The formulas and limits are the same as in the CalCash bot: the site and the bot run the same code. Here is what goes into the number.
- Protein — in grams per kilogram of body weight, and it depends on activity. Without training (sedentary): 0.83 g/kg to maintain, the adult reference intake (EFSA, population reference intakes for protein, 2012); 1.2 g/kg to lose weight, the bottom of the 1.2–1.6 g/kg range from a review of protein in weight loss (Leidy HJ et al., American Journal of Clinical Nutrition, 2015); 1.4 g/kg for gain and recomposition. From light activity (1-3 workouts a week) up: 1.8 for weight loss, 1.4 for maintenance, 1.6 for gain, 2.0 for recomposition, inside the 1.4–2.0 g/kg range for people who train (International Society of Sports Nutrition Position Stand, 2017). Where the "trains" line sits and which numbers we pick inside the ranges is our choice.
- A calorie check: protein never takes more than 35% of your daily calories, the top of the acceptable range (US Institute of Medicine, Dietary Reference Intakes summary tables, 2005). Calories are worked out the same way as in the calorie calculator: the Mifflin-St Jeor equation (Mifflin MD, St Jeor ST et al., American Journal of Clinical Nutrition, 1990) × an activity factor, for the goal you picked.
- Protein in the example foods is by raw weight from the Canadian Nutrient File (Health Canada), per 100 g: skinless chicken breast 22.5 g, 4.5% cottage cheese 11.1 g, chicken egg 11.8 g, Atlantic cod 17.8 g.
The gram target is half the story — you still have to hit it every day and see where you stand. That is where a bot that counts protein from a photo of your food helps: snap the plate and you instantly see the protein in it and how much is left to go.
Frequently asked questions
How much protein do I need per kg of body weight?
If you train, the ISSN position stand from 2017 says 1.4-2.0 g per kg a day is enough for most people; the calculator uses 1.4 for maintenance, 1.8 for fat loss, 1.6 for muscle gain and 2.0 for recomposition. If you don't train, the EFSA reference intake for adults is 0.83 g/kg, and the calculator gives 1.2 g/kg for weight loss.
How do I calculate my protein intake?
Multiply your weight in kilograms by the factor. If you train, at 70 kg cutting that is 70 × 1.8 = 126 g; maintenance 98 g; muscle gain 112 g. Without training it is 84 g cutting and 58 g at maintenance. With a lot of body fat, use lean mass instead of total weight, or the number comes out too high.
Total weight or lean mass?
If you know your body-fat percentage, work from lean mass: weight × (1 − body fat / 100). If you don't, total weight is fine for most people. The exception is carrying a lot of extra weight: then total weight noticeably overstates the target.
Can I eat too much protein?
The calculator never goes above 2.0 g/kg, the top of the ISSN range for people who train, and never lets protein take more than 35% of calories. There is little point chasing more: 1.4-2.0 g/kg covers people who train. With kidney disease protein is restricted, and a doctor sets the target.
How much protein do I need if I don't train?
Less than someone who trains. The EFSA reference intake for adults is 0.83 g/kg: 58 g a day at 70 kg, and that is exactly what the calculator gives at maintenance. When losing weight, more protein helps: a review by Leidy and colleagues (2015) suggests 1.2–1.6 g/kg, and the calculator uses 1.2. The ISSN 1.4-2.0 g/kg range comes from people who train.
Do I recalculate protein after losing weight?
Yes, every 3-4 kg — weight is multiplied directly by the factor. Five kilos down is 6-9 g less protein while cutting; the calculator gives the exact number. And definitely recalculate when the goal changes: moving from fat loss to maintenance drops about a fifth of the target if you train, and almost a third if you don't.
Reminders
Water and weight