Most keto calculators lie to you. Here's what actually matters.
If you've typed your weight into three different keto calculators and gotten three different answers, you already know the problem. Most of them use total bodyweight instead of lean mass, guess at activity level from a dropdown, and hand you a 70/25/5 ratio copied from a 2012 forum post. That's not a plan. That's a horoscope.
Keto macros come down to three numbers: a carb cap low enough to keep you in ketosis, a protein target high enough to protect muscle, and a fat intake that fills in the calories you need for your goal. Miss any one of those and you'll feel tired, stall on the scale, or lose muscle you didn't plan to lose.
Carb cap is the non-negotiable. Most adults need to stay under 20-30g net carbs per day to produce ketones reliably. Protein is the number most people underestimate. Old keto dogma said to keep protein low — recent research from Dr. Donald Layman and other metabolism researchers shows you need 0.8-1.2g per pound of lean body mass, sometimes higher on a cut. Fat is the dial, not the whole knob. You eat more fat when you want to maintain or build, less when you want to burn body fat.
This calculator uses the Mifflin-St Jeor equation against your lean mass — not your total weight — and adjusts for real activity. You enter five numbers. You get three targets. Build your day around them and most of the "why isn't keto working" questions answer themselves.
It works whether you're doing standard keto, carnivore, targeted keto for training, or anything in between. The math doesn't care what your diet is called.
Who should use this calculator
- Keto beginners who want to skip the first-week confusion and know exactly what to eat.
- Stalled keto eaters who've been at it for months and can't figure out why the scale stopped moving.
- Anyone cycling between keto and carnivore who wants the same math to work for both.
- Lifters on keto who need to protect muscle while cutting or build on a clean bulk.
Keto Macro FAQ
What are keto macros?
Keto macros are the daily ratios of fat, protein, and carbohydrates that keep your body in ketosis. The standard target is roughly 70-75% of calories from fat, 20-25% from protein, and 5-10% from carbs, though exact grams depend on your body size, activity, and goal. The real number that matters most is carbs: most people need to stay under 20-30g net carbs per day to trigger and maintain ketosis.
How many carbs can I eat on keto?
Most adults need to keep net carbs (total carbs minus fiber) under 20-30g per day to reach and stay in ketosis. Some people can flex up to 50g once fat-adapted. If you're new to keto or trying to break a stall, 20g is the safer target. Track for at least two weeks using an app like Cronometer so you're not guessing.
How much protein should I eat on keto?
Aim for 0.8-1.2g of protein per pound of lean body mass. For a 180 lb person with roughly 140 lbs of lean mass, that's 112-168g daily. Old-school keto said to keep protein low to avoid gluconeogenesis kicking you out of ketosis. Current research from Dr. Donald Layman and others shows that's overblown for most people. Higher protein protects muscle during fat loss and keeps you full.
What is the right fat ratio for keto?
Fat fills whatever calories are left after you set protein and carbs. For fat loss, eat less fat so your body pulls from stored body fat. For maintenance or performance, eat more fat to hit your calorie target. The classic 70-75% of calories from fat is a starting point, not a rule. Your protein target is fixed. Your carb target is capped. Fat is the dial you adjust.
How do I calculate my keto calories?
Start with your BMR using the Mifflin-St Jeor equation, then multiply by an activity factor to get TDEE. Subtract 500 cal/day for fat loss, add 300-500 for muscle gain, or eat at TDEE for maintenance. Our calculator handles this math and accounts for lean body mass instead of just total weight, which is a more accurate baseline.
Do I need to track keto macros forever?
No. Track strictly for 2-4 weeks until you understand portion sizes and food composition. After that, most people can eyeball it and only re-check when results stall or their goal changes. The point of tracking isn't to do it forever — it's to calibrate your intuition.
Is this keto calculator really free?
Yes. No email, no signup, no paywall on the core numbers. You get your protein target, fat target, carb cap, and daily calories the moment you finish. There's an optional $29 upgrade for a 30-day meal plan, a doctor conversation script, and a plateau protocol. The free version gives you everything you need to start.
What's the difference between keto and carnivore?
Keto allows 20-50g of carbs from vegetables, nuts, and low-carb foods. Carnivore eliminates all plants — just meat, eggs, and animal products. Both achieve ketosis. Keto has more food variety. Carnivore is simpler and tends to run higher protein. The macro math is nearly identical; only the carb source changes. Same calculator works for both.