Protein Intake Calculator
Calculate how many grams of protein you need each day based on your weight and goal.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
Estimate daily protein from body weight and a selected scenario. The 0.8 g/kg option reflects the adult RDA; higher options are training scenarios, not personalized prescriptions. Per-meal protein divides the daily estimate across three meals. Individual needs vary; people with kidney disease or other medical conditions should ask a clinician.
Worked example
calculated with the default values below
Body weight 75 kg · Goal Resistance-training scenario Daily protein 120 g · Protein across 3 meals 40 g · Protein per kg 1.60 g/kg · Calories from protein 480 kcal
General background references
Disclaimer
These calculators are for general information only and are not a medical device, a diagnosis or a treatment plan. Reference ranges describe populations, not individuals, and do not account for pregnancy, medication, disability or athletic training. Discuss your own situation with a qualified healthcare professional.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
P = w × r; Pm = P ÷ 3; E = 4P
- w
- Body weight
- r
- Protein per kg for the goal
- P
- Protein per day (g)
- Pm
- Per meal (3 meals)
- E
- Calories from protein (kcal)
Daily protein = body weight in kg × selected g/kg scenario. Per-meal amount divides by three; calories use 4 kcal per gram. The 0.8 g/kg option is the adult RDA reference; higher values are selectable scenarios and not individualized medical advice.
Frequently asked questions
What does the 0.8 g/kg protein option represent?
It reflects the adult Recommended Dietary Allowance reference for generally healthy adults. The higher options are selectable training scenarios, not a personalized prescription. A 2018 meta-analysis of resistance-training studies found no further fat-free-mass gains beyond about 1.6 g/kg/day on average, with a breakpoint confidence interval of 1.03–2.20; that result does not establish an ideal intake for every person. [Study summary](https://pubmed.ncbi.nlm.nih.gov/28698222/).
Why does choosing a strength goal raise my protein number so much?
Daily protein is simply body weight times the goal factor, so the 75 kg default at 1.6 g/kg gives 120 g a day, or 480 kcal since protein carries 4 kcal per gram. Switch the goal to 0.8 for general health and the same person drops to 60 g; pick 2.2 for heavy training and it rises to 165 g. The factor, not your weight, drives the swing.