UNDERSTAND THE METHOD
How to use this calculator
Choose your activity and planning goal. Compare the whole range instead of treating its midpoint as a precise requirement. If you enter body fat, the calculation uses a lean-mass scaling convention. The table shows how the same assumptions change across activity categories.
What the result can tell you
The exact category increments and lean-mass scaling are calculator conventions. They do not establish individual optimal intake. Published daily allowances use reference body weights. Illness and medical nutrition needs require other assessment.
Daily protein in grams by body weight
Both tables are for adults under 65 with the maintain-weight goal, using total body weight. The calculator starts from a grams-per-kilogram rate for each activity level. The lowest level begins at 0.8 g/kg a day, the adult recommended dietary allowance. The higher levels are this calculator's own planning steps. For comparison, the ISSN position stand discusses 1.4 to 2.0 g/kg a day for most people who exercise.
Planning rates by activity level
| Activity level | Grams per kg | Grams per lb |
|---|---|---|
| Sedentary | 0.8 to 1.0 | 0.36 to 0.45 |
| Lightly active | 1.0 to 1.2 | 0.45 to 0.54 |
| Moderately active | 1.2 to 1.4 | 0.54 to 0.64 |
| Active | 1.4 to 1.6 | 0.64 to 0.73 |
| Very active | 1.6 to 1.8 | 0.73 to 0.82 |
| Athlete | 1.8 to 2.2 | 0.82 to 1.00 |
Grams of protein per day by body weight
| Body weight | Sedentary | Moderately active | Very active | Athlete |
|---|---|---|---|---|
| 120 lb (54 kg) | 44 to 54 | 65 to 76 | 87 to 98 | 98 to 120 |
| 140 lb (64 kg) | 51 to 64 | 76 to 89 | 102 to 114 | 114 to 140 |
| 160 lb (73 kg) | 58 to 73 | 87 to 102 | 116 to 131 | 131 to 160 |
| 180 lb (82 kg) | 65 to 82 | 98 to 114 | 131 to 147 | 147 to 180 |
| 200 lb (91 kg) | 73 to 91 | 109 to 127 | 145 to 163 | 163 to 200 |
| 220 lb (100 kg) | 80 to 100 | 120 to 140 | 160 to 180 | 180 to 220 |
| 240 lb (109 kg) | 87 to 109 | 131 to 152 | 174 to 196 | 196 to 239 |
The goal option moves these rates up: build muscle adds 0.2 g/kg, lose weight adds 0.3 g/kg and endurance training adds 0.1 g/kg. From age 65, any level below 1.0 to 1.2 g/kg is raised to that range, in line with the PROT-AGE group's advice for older adults. These are planning ranges for healthy adults, not a personal requirement. Kidney disease and other medical conditions need a clinician's advice.
Common questions
What changes the protein planning range?
Activity, planning goal, and calculation basis change the range. A known body-fat input uses a lean-mass scaling convention; otherwise the calculation uses total body weight.
Is the midpoint a precise personal requirement?
No. Compare the full range. The category increments and lean-mass scaling are calculator conventions, and illness or medical nutrition needs require another assessment.
Sources & limitations4 sources
Sources checked September 12, 2026. These notes identify methods and assumptions. They have not received an independent clinical review.
- PROT-AGE describes older-adult protein reference ranges.pubmed.ncbi.nlm.nih.gov
- Official protein RDA table uses reference body weights and separate life stages.canada.ca
- ISSN reviews protein and exercise evidence.pubmed.ncbi.nlm.nih.gov
- Adult protein reference intake and life-stage values.nap.nationalacademies.org