What this tool does
Protein is calculated from body weight using the selected weight-based target. Fat receives the selected percentage of daily calories, and carbohydrates receive the calories left after protein and fat. If the settings cannot fit inside the calorie target, the calculator stops and explains the conflict instead of returning impossible macros. US units are shown first, with Metric available at any time.
How to use it
- Choose US or Metric units, then enter your daily calorie target and current body weight.
- Choose the protein target that matches your planning preference.
- Set the percentage of calories you want to allocate to fat.
- Review the resulting grams and percentages, then adjust the inputs if your preferences require a different split.
Important limitations
These numbers are planning estimates, not a diagnosis or individualized medical advice. They can be less appropriate during pregnancy, breastfeeding, adolescence, illness, recovery from an eating disorder, or when a clinician has given you specific nutrition instructions.
Frequently asked questions
Do the macro percentages always add to exactly 100%?
They can differ by a small amount because gram targets are rounded to whole numbers.
Why does the calculator sometimes reject my settings?
A high protein target plus a high fat percentage can consume more calories than the total allows. The tool rejects that impossible combination instead of creating negative carbohydrates.
Can I use pounds or kilograms?
Yes. US pounds are shown first, and you can switch to kilograms. Both inputs are converted into the same underlying calculation.