The calculator gives you two ways to look at your targets, grams and percentages. Both matter but for different reasons.
Grams are what you track day to day. Hit your protein target in grams first, everything else adjusts around it. A common starting point is 1.6–2.2g of protein per kg of bodyweight.
Percentages show you how your calories are distributed across the three macros. They're useful for comparing diet styles, a ketogenic diet is around 70% fat, while a high-carb diet might be 50% carbs.
The two numbers are linked, change one and the other updates. Use grams to build your meals, use percentages to understand your overall diet balance.