How to Use the Calculator
- Enter your daily calories. Use the target you're aiming for. If you don't have one, the TDEE calculator estimates your maintenance calories and a target for losing or gaining weight.
- Enter your body weight. Protein is worked out from it, in grams per kilogram.
- Choose a protein level. 1.6 g/kg is about where extra protein stopped adding muscle in strength training studies (more below). Pick a lower level if you exercise lightly, or 2.0 g/kg if you want more.
- Choose a fat share. 30% is a middle setting. Carbs get whatever calories are left.
How the Calculator Splits Your Calories
Each macro has a fixed number of calories per gram: 4 for protein, 4 for carbs, and 9 for fat. The calculator sets protein first, in grams for your body weight, then takes your chosen share of calories for fat. The calories left over go to carbs. FITIV Pulse uses the same 4, 4, and 9 when it shows each macro's share of the calories you've eaten.
Setting protein by body weight, rather than as a percentage, keeps it steady when your calories change. At 160 lb and 1.6 g/kg, the target is 116 g whether you eat 1,800 or 2,400 calories. As a percentage, that would be 26% of one and 19% of the other.
How Much Protein Do You Need?
The Recommended Dietary Allowance for adults is 0.8 grams of protein per kilogram of body weight a day. It's set as the minimum needed to avoid losing body protein, not the amount that best supports training (Wolfe et al., 2017).
For people who exercise, the International Society of Sports Nutrition puts the range at 1.4 to 2.0 g/kg a day, and says even more may help resistance-trained people keep muscle while eating in a deficit (Jäger et al., 2017).
Here's what each protein level in the calculator works out to for a 160 lb (72.6 kg) person:
| Protein level | Grams per kg | Grams per lb | Grams a day at 160 lb |
|---|---|---|---|
| Minimum (RDA) | 0.8 | 0.36 | 58 |
| Regular exercise | 1.4 | 0.64 | 102 |
| Strength training | 1.6 | 0.73 | 116 |
| High | 2.0 | 0.91 | 145 |
If you take a GLP-1 medication, protein needs extra attention, because a share of the weight you lose can come from muscle. Our guide to GLP-1 and muscle loss covers the protein targets suggested for people on these medications.
Fat and Carbs: Splitting the Rest
The National Academies, which set US nutrient guidelines, give adults a range for each macro as a share of calories: 20–35% from fat, 45–65% from carbohydrates, and 10–35% from protein (National Academies). The calculator's fat settings stay inside that range, and it tells you when carbs or protein land outside theirs.
With higher protein and a lower calorie target, carbs can drop below 45%. That's expected with this kind of split. If you'd like more carbs, lower the fat setting or raise your calories.
Example: Macros at 1,700 Calories
Say you weigh 160 lb and you're eating about 1,700 calories a day to lose a pound a week (the example on the TDEE calculator page works out to 1,704). At 1.6 g/kg of protein and 30% fat:
- Protein: 72.6 kg × 1.6 = 116 g (464 calories, 27%)
- Fat: 30% of 1,700 = 510 calories = 57 g
- Carbs: 1,700 − 464 − 510 = 726 calories = 181 g (43%)
Carbs come out just under 45%. Dropping fat to 25% gives 47 g of fat and 203 g of carbs, which puts carbs at 48%.
How FITIV Shows Your Macros
FITIV Pulse doesn't log food itself. It reads what you log in a food app that saves to Apple Health. Tap the Energy card on the Today tab to see Macros: the grams of carbs, protein, and fat you've eaten today, with a chart of each one's share of your calories once all three are logged. You can compare those numbers with the targets from this calculator.
The same macros are available as a Macronutrients widget and Apple Watch complication, so you can check them without opening the app. For the calorie side, the Energy card compares what you eat with what you burn and shows your deficit or surplus, and Weight Management tracks whether your weight is moving at the pace you set.
Frequently Asked Questions
How many grams of protein per pound of body weight?
Divide the grams per kilogram by 2.2. The adult minimum of 0.8 g/kg is about 0.36 g per pound, and 1.6 g/kg, about where gains leveled off in strength training studies, is about 0.73 g per pound. For a 160 lb person, that's 58 g and 116 g a day.
Should I base protein on my current weight or my goal weight?
The research ranges are set per kilogram of body weight. If you have a lot of weight to lose, a target based on current weight can be hard to eat, so some guidance, including FITIV Pulse's GLP-1 articles, bases protein on goal weight instead. Either way, pick a target you can reach most days.
What's a good macro split for weight loss?
Your calorie total decides whether you lose weight. Protein is the part of the split that matters most for keeping muscle while you eat less. A common approach is to keep protein high, around 1.6 g/kg or more, set fat between 20% and 35% of calories, and let carbs fill the rest.
Does FITIV Pulse track macros?
It shows them but doesn't log food itself. Log your meals in a food app that saves to Apple Health, and FITIV Pulse shows the day's carbs, protein, and fat when you tap the Energy card, plus a Macronutrients widget and Apple Watch complication.
