Free keto calculator
Find your keto macros in two seconds. Enter your weight, height, age, activity, and goal — the calculator returns your daily calorie target and your fat, protein, and net-carb grams (and percentages), with the carb cap and protein target fully adjustable — updated live, as you type.
On this page15 sections
| Fat | 227 g (75%) |
| Protein | 141 g (21%) |
| Net carbs | 25 g (4%) |
| Calorie target | 2,711 cal |
Activity: Moderate (×1.55). Net carbs are fixed at your cap and protein is set from bodyweight; fat fills the rest of the calorie budget.
Estimates only; individual metabolism and ketosis thresholds vary. How many carbs can you eat on keto?
Results are estimates. Consult a professional.
What is a keto macro calculator?
A keto macro calculator turns your body stats and goal into a daily eating target for the ketogenic diet: how many calories to eat, and how to split them across fat, protein, and net carbs. Keto is a high-fat, very-low-carb way of eating that pushes your body out of burning glucose and into burning fat for fuel — a metabolic state called ketosis. The hard part is hitting the right numbers, and that is exactly what this calculator does the moment you enter your weight, height, age, activity, and goal.
Unlike a general macro split, a keto plan is built around one non-negotiable: carbohydrate has to stay low enough to keep you in ketosis. So instead of asking you to pick three percentages, a keto calculator fixes net carbs low, sets protein from your bodyweight, and lets fat fill the rest of your calorie budget. The result is the classic keto macro ratio — roughly 70–75% fat, 20–25% protein, and about 5% carbs.
Keto macros vs standard macros
A standard macro calculator might hand you 40% carbs, 30% protein, and 30% fat. Keto flips that. Carbs drop to a fixed 20–50 g a day, protein stays moderate (high protein can blunt ketosis), and fat becomes the dominant fuel. That inversion — carbs down, fat up — is what separates a keto macro plan from any other calorie split.
How the keto calculator sets your macros
The calculator works in four steps — the same sequence used by Ruled.me, Perfect Keto, and Diet Doctor. Each step feeds the next.
- Find your BMR. Your basal metabolic rate — the calories you burn at complete rest — comes from the Mifflin-St Jeor equation, the most accurate common formula, using your weight, height, age, and sex.
- Scale it to TDEE. Your total daily energy expenditure multiplies BMR by an activity factor (1.2 sedentary up to 1.9 for an athlete) to capture what you actually burn in a day.
- Adjust for your goal. Maintain keeps calories at TDEE; lose cuts 20%; gain adds 10%. This sets your daily calorie target.
- Split into keto macros. Net carbs are fixed at your chosen cap, protein is set from your bodyweight, and fat takes every calorie that's left over.
Why carbs are capped, protein is moderate, and fat is high
Why net carbs are capped low
Carbohydrate is the one macro that can knock you out of ketosis, so it's the limit everything else is built around. Most keto plans cap intake at 20–50 g of net carbs a day, with many people aiming for 20–30 g. Restricting carbs far enough is the single most important factor for reaching and holding ketosis — fat and protein matter for body composition, but carbs decide whether you're in ketosis at all.
Why protein is kept moderate
Keto is a moderate-protein, not high-protein, diet. Protein is set from your bodyweight — commonly 0.6–1.0 g per pound — to preserve muscle while you're in a calorie deficit. It's kept moderate because the body can convert excess protein into glucose through gluconeogenesis, which in some people nudges blood sugar up and can make ketosis harder to hold. Enough to protect muscle, not so much that it works against the diet.
Why fat is the lever that fills the rest
Once carbs and protein are set, fat is whatever calories remain — and on keto that's most of them, because fat is the fuel replacing carbohydrate. This is why fat is calculated last and as a remainder rather than a fixed target: it flexes to hit your calorie goal. Eat more fat to maintain or gain, less to lose, while carbs and protein stay put.
A worked example using the keto calculator
Sarah is 35, weighs 70 kg (154 lb), is 165 cm tall, and is moderately active. She wants to lose weight on keto, with a 25 g net-carb cap and protein at 0.8 g per pound. Here is how the calculator gets to her macros.
Step 1 — Find TDEE and the calorie target
Her Mifflin-St Jeor BMR is about 1,395 calories. At a moderate activity factor (×1.55) that's a TDEE of 2,163 calories. Losing weight cuts 20%, so her target is 2,163 × 0.80 = 1,730 calories a day.
Step 2 — Set protein and net carbs
Protein comes from bodyweight: 154 lb × 0.8 g/lb = 123 g protein (about 494 calories). Net carbs are fixed at her cap: 25 g (100 calories).
Step 3 — Fat fills the rest
Whatever calories remain go to fat: (1,730 − 494 − 100) ÷ 9 = 126 g fat (about 1,136 calories). The three add back to her 1,730-calorie target exactly.
| Macro | Grams/day | Calories | % of target |
|---|---|---|---|
| Fat | 126 g | 1,136 | 66% |
| Protein | 123 g | 494 | 28% |
| Net carbs | 25 g | 100 | 6% |
| Total | — | 1,730 | 100% |
Sarah's keto macros at a 1,730-calorie target — the literal output of the calculator above.
Keto macro ratios: standard, moderate, and high-protein
There isn't one single keto ratio — it's a band. Where you land depends mostly on how much protein you set, since carbs stay low and fat fills the rest. These are the common targets keto calculators use.
| Approach | Fat | Protein | Carbs | Best for |
|---|---|---|---|---|
| Standard keto | 70–75% | 20–25% | ~5% | Most people; the default split |
| High-protein keto | 60–65% | 30–35% | ~5% | Preserving muscle, heavy training |
| Very-high-fat (therapeutic) | 75–80% | 15–20% | ~5% | Strict/medical keto, appetite control |
Carbs stay near 5% across all variants; the trade-off is between fat and protein. The standard 70% fat / 25% protein / 5% carb split is the most common starting point.
Net carbs vs total carbs on keto
Most keto plans count net carbs, not total carbs. Net carbs are the carbohydrate your body actually digests and that can affect ketosis — you get them by taking total carbohydrate and subtracting fiber and most sugar alcohols, which pass through largely unabsorbed.
Counting net carbs is what lets keto eaters fit fibrous vegetables, nuts, and berries under a 20–30 g cap — a cup of raspberries is ~15 g total carbs but only ~7 g net. To check any food against your cap, use the net carbs calculator; to build the rest of your day, pair this with the macro calculator and the calorie calculator.
How many carbs can you eat on keto?
For most people, staying under 20–50 g of net carbs a day is enough to reach and hold ketosis, with 20–30 g the common sweet spot. The exact number is individual — some people stay in ketosis at 50 g, others need to drop closer to 20 g, especially when starting out or if they're insulin-resistant.
- 20 g or less — the strictest, most reliable for getting into ketosis quickly. A good starting point for the first few weeks.
- 20–30 g — the standard keto range most calculators default to; sustainable for most people long-term.
- 30–50 g — a more relaxed ceiling that works for some, particularly very active people who burn through glycogen.
The calculator defaults to 25 g of net carbs, but you can set yours anywhere from 20 to 50. If you're not sure you're in ketosis, tighten the cap before changing anything else — carbs are the lever that matters most.
How much protein on keto?
Keto protein is usually set per pound of bodyweight, in the 0.6–1.0 g per pound range. The right target depends on your goal: lean toward the lower end if you're sedentary and mainly want to lose fat, and toward the higher end if you train hard or want to protect muscle in a deficit.
- 0.6 g/lb — minimal, for sedentary people prioritizing the deepest ketosis.
- 0.8 g/lb — the moderate default; protects muscle for most people. This is the calculator's starting value.
- 1.0 g/lb — higher, for active people, lifters, or anyone losing weight who wants to keep as much muscle as possible.
Worried about 'too much protein' kicking you out of ketosis? For most people that fear is overstated — moderate protein in this range is fine. The bigger risk is too little, which costs you muscle. Set protein adequately and control carbs; that's the order that matters.
Tips for hitting your keto macros
A few habits make keto macros far easier to hit and hold:
- Lock carbs first. Hit your net-carb cap every day before worrying about fat and protein. Carbs decide whether you're in ketosis; the other two fine-tune your results.
- Treat protein as a target, not a ceiling. Aim to reach your protein number — it protects muscle. You don't need to fear going slightly over.
- Use fat to hit calories, not as a goal in itself. Add fat to reach your target if you're short, but don't force extra fat once you're full — especially when losing weight.
- Count net carbs from labels carefully. Subtract fiber on US labels; on EU/UK labels the carb figure already excludes it. Recheck when products lean on maltitol.
- Re-run the numbers as your weight changes. Protein and calories both shift with bodyweight, so recalculate every 10–15 lb.
Data sources and methodology
This calculator estimates calories from the Mifflin-St Jeor equation (Mifflin MD, St Jeor ST et al., American Journal of Clinical Nutrition, 1990) for BMR, scaled to TDEE by standard activity factors, then adjusted for your goal (maintain, lose −20%, gain +10%). The keto split — net carbs fixed low, protein from bodyweight, fat as the remainder — follows the consumer keto-macro conventions used by Ruled.me, Perfect Keto, Diet Doctor, and the Omni and Healthy Eater keto calculators. Macros use the Atwater energy values of 4 kcal/g for protein and carbohydrate and 9 kcal/g for fat.
Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr, 1990.Diet Doctor — How much fat, protein, and carbs on a keto diet.Frequently asked questions about the free keto calculator
About this keto macro calculator
This keto calculator runs entirely in your browser. The figures you enter stay on your device — nothing is sent to a server, logged, or shared. It estimates calories with the Mifflin-St Jeor equation scaled to your activity and goal, then fixes net carbs at your cap, sets protein from your bodyweight, and lets fat fill the rest of the calorie budget — updating instantly as you type.
Calculators Cloud offers 400+ free tools with no sign-up. The whole Health calculators shelf includes Macros, Net carbs, TDEE, and Calorie tools alongside this one. Or browse the full calculator directory.