How much protein do you actually need?
More than you're probably eating. Active people do best around 1.6 to 2.2 grams per kilogram of body weight per day — roughly double the 0.8 g/kg minimum set for sedentary adults. For a 70 kg person who trains regularly, that's 112 to 154 grams daily, not the 40-gram chicken-breast-and-hope approach most people are running.
I know, that number sounds like a lot the first time you see it. It sounded like a lot to me too. Then I tracked for a week and realized I'd been eating like a bird and wondering why I was always hungry and never recovering. Protein is the macro almost everyone undereats, and it's the one that moves the needle most.
But protein is only one third of the picture. To set all three macros sensibly, you need to know how many calories you're working with — which means a quick detour through the least intimidating math in nutrition.
Start with calories: BMR and TDEE, minus the mystique
Your body burns calories just keeping the lights on — that's your Basal Metabolic Rate (BMR). The most validated formula for estimating it is Mifflin-St Jeor, and it's simpler than it looks:
- Men: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Then multiply by an activity factor to get TDEE — Total Daily Energy Expenditure, the calories you actually burn in a day:
- Sedentary (desk job, minimal exercise): BMR × 1.2
- Lightly active (1–3 workouts/week): BMR × 1.375
- Moderately active (3–5 workouts/week): BMR × 1.55
- Very active (6–7 hard sessions): BMR × 1.725
Be honest here. Most of us are one category less active than we claim — "moderately active" office workers are usually "lightly active" at best. Overestimating is how people end up eating at "maintenance" and gaining a kilo a month.
Protein: the anchor macro
Set protein first, because it's the least negotiable:
- Training hard / building muscle: 1.6–2.2 g per kg
- Lightly active or over 50: 1.2–1.6 g per kg (older adults need more, not less — muscle loss accelerates with age)
- Sedentary: at least 0.8 g per kg, the floor, not the target
Why the fuss? Protein is the most satiating macro — it keeps you full on fewer calories — and it's the raw material for muscle repair. Skimp on it during a diet and a frustrating share of the weight you lose will be muscle, not fat. That's how people get lighter but somehow look exactly the same.
Fat: the floor, not the enemy
Fat got a bad decade in the '90s and we're still recovering. You need a minimum of roughly 0.5 to 1 gram per kilogram for hormone production — testosterone, estrogen, all the behind-the-scenes chemistry. Drop below that floor for long and things get weird: tanked energy, wrecked sleep, vanished libido.
For most people, landing somewhere around 20–30% of total calories from fat works well. Favor the usual suspects — olive oil, nuts, fatty fish — but don't stress about perfection. The floor matters more than the source.
Carbs: fill the bucket
Here's the liberating part: after protein and fat are set, carbohydrates get whatever calories are left. Carbs are your training fuel — they power hard sessions and refill muscle glycogen. Endurance athletes and heavy lifters thrive on more; desk workers cutting weight do fine on less. There's no moral dimension to it, despite what the internet says. They're just the flexible macro.
A worked example: a full day, real numbers
Meet our example: a 32-year-old woman, 68 kg, 165 cm, training 4 days a week.
BMR = (10 × 68) + (6.25 × 165) − (5 × 32) − 161 = 680 + 1,031 − 160 − 161 = 1,390 calories. Moderately active: 1,390 × 1.55 = ~2,155 calories TDEE.
Now the macros:
- Protein: 2.0 × 68 = 136 g (544 cal)
- Fat: 60 g, about 25% of calories (540 cal)
- Carbs: the remainder — (2,155 − 544 − 540) ÷ 4 = ~268 g (1,071 cal)
A day that hits it: Greek yogurt with berries and granola at breakfast (~35 g protein), a big chicken rice bowl at lunch (~45 g), a protein shake and banana pre-workout (~30 g), salmon with potatoes and vegetables at dinner (~40 g). Nothing exotic, no six-meal Tupperware regime — just normal food in the right amounts. If you want your own numbers instead of hers, the macro calculator does this whole chain in about thirty seconds.
Frequently asked questions
Can I build muscle and lose fat at the same time?
Sometimes — it's called recomposition, and it works best for beginners, people returning after a layoff, and those carrying more body fat. The requirements are non-negotiable though: high protein (top of the range), progressive training, and only a slight calorie deficit. Lean, experienced lifters generally have to pick one goal at a time.
Do I need to hit my macros exactly every day?
No. Your body runs on weekly averages, not daily perfection. If you're within 10% most days and the weekly totals land right, you'll get 95% of the results. The people who burn out are the ones treating a 12-gram carb overshoot like a moral failure. Consistency beats precision.
Is high protein bad for your kidneys?
For healthy kidneys, no — this is one of nutrition's most durable myths. The confusion comes from the fact that people with existing kidney disease are told to limit protein, which got telephone-gamed into "protein causes kidney disease." Multiple long-term studies on healthy adults show no kidney damage at intakes up to and beyond 2 g/kg. Drink water, you'll be fine.
What if I'm vegetarian or vegan?
Entirely doable, with one adjustment: aim for the top of your protein range. Plant proteins are slightly less digestible and often low in one essential amino acid, so variety matters — combine legumes, grains, soy, and nuts across the day. A vegan lifter at 2.2 g/kg does just as well as an omnivore at 1.8. It takes more planning, not more suffering.
Related tools
You can also use Explore all free online tools and Read more helpful articles as part of your workflow.
Using a how many macros per day can make this task easier and more efficient when you need a simple online solution.
A how many macros per day is especially useful when you want a quick browser-based workflow.