Adult arithmetic workspace only. Calories are entered by you; this tool does not prescribe them. Not for children, pregnancy, eating-disorder care, diagnosis, or treatment. Consult a qualified clinician or dietitian for individualized guidance.
Adult screening estimate only, not a diagnosis. Body composition, age, pregnancy, medical history, and population-specific risk can change interpretation; discuss health decisions with a qualified clinician.
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How this calculator works
Formula
Protein grams = weight kg × selected grams/kg. Fat grams = entered calories × fat share ÷ 9. Carbohydrate grams are the calorie remainder ÷ 4, using 4 kcal/g for protein and carbohydrate and 9 kcal/g for fat.
Worked example
At a user-selected 2,400 calories, 80 kg, 1.6 g/kg protein, and 30% fat, the arithmetic yields 128 g protein, 80 g fat, and 292 g carbohydrate.
Assumptions to verify
- The user—not the calculator—selects the calorie total and macro assumptions.
- The workspace is limited to adults who confirm age 18 or older.
- Clinical conditions, pregnancy, eating-disorder care, allergies, medications, and individualized nutrition needs are not modeled.
Frequently asked questions
Does this prescribe calories?
No. The calorie total is entered by you; this tool only performs arithmetic.
Why is carbohydrate the remainder?
Protein and fat assumptions are allocated first, then remaining calories are divided by 4 kcal per gram.
Who should not rely on this tool?
Children, pregnant people, people receiving eating-disorder care, and anyone needing clinical nutrition guidance should consult a qualified professional.
Privacy: Inputs and results stay in this browser. Any future sponsored recommendation or advertisement will be clearly labeled and kept separate from the calculation.