Protein Calculator

What the RDA actually is

The Recommended Dietary Allowance for protein is 0.8 grams per kilogram of body weight per day. That number is set to meet the needs of 97-98% of healthy adults — it is the amount below which deficiency becomes likely, not the amount at which anything is optimized. In the Dietary Guidelines appendix the same figure appears in grams for reference body weights: 56 g/day for men aged 19 and over, 46 g/day for women. If your weight is far from those reference weights, the per-kilogram figure is the one to use.

Why athletes are told to eat more

Higher intakes, usually quoted between 1.2 and 2.0 g/kg, come from position stands published by sports-nutrition and dietetics organizations, not from any federal agency. That distinction matters and this page keeps it visible: the RDA is a government reference value, the training ranges are professional consensus about performance and body composition. They answer different questions and neither replaces the other.

Protein while losing weight

In a calorie deficit the body will break down muscle for amino acids unless there is enough protein coming in and a reason to keep the muscle — which is what resistance training supplies. This is the one situation where the evidence for a higher intake is strongest, and where the gram figure is usually set against lean body mass rather than total weight, because fat tissue has little protein requirement of its own.

The AMDR, and why there is an upper end

The Acceptable Macronutrient Distribution Range puts protein at 10-35% of calories for adults, 10-30% for children aged 4-18 and 5-20% for ages 1-3. The upper end is not a toxicity limit; it exists because calories spent on protein are calories not spent on carbohydrate and fat, and pushing too far crowds out nutrients those provide. For healthy kidneys there is no good evidence that intakes in this range cause harm, but the picture is different in existing kidney disease, which is exactly when a doctor should set the number instead of a calculator.

Spreading it across the day

Total daily intake matters most, but distribution is not irrelevant: muscle protein synthesis responds to a dose in a single sitting, so several moderate servings tend to beat one very large one. The per-meal figure here is simply your daily target divided by the number of meals — a planning aid, not a threshold. Plant proteins are lower in some essential amino acids than animal ones, so a plant-based diet needs a wider variety of sources to cover the same ground, and the total may need to be slightly higher.

Frequently Asked Questions