Last updated:
Protein Calculator
A 70 kg adult who strength-trains four times a week may need 112–154 g of protein daily – almost double the generic “60 g” still printed on some food labels. Miscalculating your intake by 30–40 g per day can mean the difference between steady progress and a months-long plateau. The protein calculator below removes the guesswork by tailoring a daily target to your body weight, activity level, and goal.
How much protein do you need per day?
The Recommended Dietary Allowance (RDA) set by the U.S. National Academy of Medicine is 0.8 g per kg of body weight (0.36 g per lb) for a sedentary adult. That number covers the minimum to prevent deficiency – not the amount that supports athletic performance, fat loss, or healthy aging.
Research published in the British Journal of Sports Medicine and endorsed by the International Society of Sports Nutrition (ISSN) shows that active people benefit from significantly more:
| Activity level & goal | Protein (g / kg body weight) | Protein (g / lb body weight) |
|---|---|---|
| Sedentary adult (RDA) | 0.8 | 0.36 |
| Recreational exercise 3× / week | 1.0–1.2 | 0.45–0.55 |
| Endurance athlete | 1.2–1.6 | 0.55–0.73 |
| Strength / muscle building | 1.6–2.2 | 0.73–1.0 |
| Fat loss with muscle retention | 1.8–2.4 | 0.82–1.1 |
| Older adult (65+) | 1.0–1.2 | 0.45–0.55 |
| Pregnant or breastfeeding | 1.1–1.3 | 0.5–0.6 |
The calculator applies these multipliers automatically based on the inputs you select.
How does the protein calculator work?
The calculator uses a three-step formula:
- Convert weight to kilograms – if you enter pounds, it divides by 2.205.
- Select a multiplier – determined by your activity level and goal (see the table above).
- Multiply – body weight in kg × multiplier = daily protein target in grams.
For example, an 80 kg person aiming to build muscle:
- 80 kg × 1.8 (mid-range for strength training) = 144 g of protein per day.
If the same person is in a calorie deficit to lose fat while keeping muscle, the multiplier shifts to 2.0–2.2:
- 80 kg × 2.1 = 168 g of protein per day.
How to choose your activity level
The multiplier depends on how often and how intensely you move, not just whether you “work out.” Use these descriptions:
- Sedentary – desk job, little to no structured exercise, fewer than 5,000 steps per day.
- Lightly active – 1–3 sessions per week of moderate exercise, or a job with some walking.
- Moderately active – 3–5 sessions per week including resistance or endurance training.
- Very active – 6–7 sessions per week, or a physically demanding job plus training.
- Extremely active – twice-daily training, competitive athletes, or heavy manual labor.
Protein targets by fitness goal
Muscle building (hypertrophy)
A calorie surplus of 200–400 kcal combined with 1.6–2.2 g/kg protein supports lean mass gains. Going above 2.2 g/kg does not produce additional muscle in most studies – the excess is oxidized for energy.
Fat loss with muscle retention
In a calorie deficit, protein needs increase because your body breaks down more amino acids for energy. A range of 1.8–2.4 g/kg preserves lean mass, especially when combined with resistance training. Heavier deficits (25%+ below maintenance) push the requirement toward the upper end.
Maintenance and general health
For weight maintenance without specific performance goals, 1.0–1.2 g/kg is sufficient. This range also supports satiety, which helps prevent unintentional weight gain.
Pregnancy and breastfeeding
The RDA for pregnant women is 1.1 g/kg (an additional ~25 g/day in the second and third trimesters). Breastfeeding mothers need roughly 1.3 g/kg. The calculator factors this in when you select the relevant option.
Factors that change your protein needs
Body composition. People with higher body fat percentages can calculate protein based on lean body mass (LBM) rather than total weight for a more precise target. LBM = total weight − fat mass. A simple estimate: LBM = body weight × (1 − body fat % / 100).
Age. After 65, anabolic resistance reduces the body’s efficiency in using dietary protein. Intakes of 1.0–1.2 g/kg, combined with resistance training, significantly reduce sarcopenia risk according to a 2024 meta-analysis in The American Journal of Clinical Nutrition.
Injury or illness. Surgery, fractures, and burns can double protein turnover. Clinical guidelines recommend 1.5–2.0 g/kg during recovery, under medical supervision.
Dietary protein quality. Animal-based sources (eggs, dairy, meat, fish) have a Digestible Indispensable Amino Acid Score (DIAAS) of 100+. Most plant sources score 60–90. If you eat primarily plant-based protein, add 10–20% to your calculated target.
High-protein foods to hit your target
| Food | Serving | Protein (g) | Calories |
|---|---|---|---|
| Chicken breast (cooked) | 100 g | 31 | 165 |
| Greek yogurt (0% fat) | 170 g | 17 | 100 |
| Eggs (whole, large) | 2 eggs | 12 | 144 |
| Cottage cheese (2%) | 113 g | 14 | 92 |
| Salmon (cooked) | 100 g | 25 | 206 |
| Lentils (cooked) | 100 g | 9 | 116 |
| Tofu (firm) | 100 g | 17 | 144 |
| Whey protein isolate | 1 scoop (30 g) | 25 | 113 |
| Almonds | 28 g (23 nuts) | 6 | 164 |
| Black beans (cooked) | 100 g | 8.9 | 132 |
A 150 g protein target could look like this in practice: 3 eggs at breakfast (18 g), 150 g chicken at lunch (46 g), a whey shake post-workout (25 g), 150 g salmon at dinner (38 g), and 170 g Greek yogurt as a snack (17 g) – total 144 g, with room for protein from grains and vegetables pushing it past 150 g.
Common mistakes when tracking protein
Ignoring incidental protein. A slice of whole-wheat bread (4 g), a cup of broccoli (2.5 g), and a tablespoon of peanut butter (4 g) add up. Over a full day, “trace” sources contribute 20–40 g.
Using raw-weight data for cooked food. Meat loses 20–30% of its weight during cooking. 100 g of cooked chicken breast is roughly 130–140 g raw. If you log cooked weight against raw-weight nutrition data, you will overestimate your intake by 25–30%.
Counting only complete proteins. Your body pools amino acids over the course of a day. You do not need to combine complementary plant proteins in the same meal – just eat a varied diet across the day.
This calculator provides general estimates based on published nutritional guidelines. Individual needs vary; consult a registered dietitian or physician for medical or clinical advice.
Frequently Asked Questions
Can I eat too much protein?
Healthy kidneys can process up to 2.2 g per kg of body weight without issues. Going significantly above 3.5 g/kg long term may strain renal function in people with pre-existing conditions. Most adults stay well within safe limits at 1.6–2.2 g/kg.
Does protein timing matter?
Total daily intake matters far more than timing. That said, spreading protein across 3–5 meals with 25–40 g each maximizes muscle protein synthesis better than concentrating most of it in one meal.
Is plant protein as effective as animal protein?
Plant proteins are slightly less bioavailable and often lack one essential amino acid. Combining sources like beans and rice, or simply eating 10–20% more total protein, fully compensates for the difference.
Do older adults need more protein?
Yes. After age 65, an intake of 1.0–1.2 g/kg helps counteract age-related muscle loss (sarcopenia). During illness or recovery, needs may rise to 1.2–1.5 g/kg.
Should I count protein from grains and vegetables?
Absolutely. Bread, pasta, oats, and even broccoli contribute protein – typically 3–8 g per serving. Tracking all sources gives a more accurate picture of your actual intake.