What are keto macros?
On a ketogenic diet you keep carbohydrate very low so your body shifts from burning glucose to burning fat for fuel — a state called ketosis. “Macros” are the three macronutrients you plan around: fat, protein, and net carbs. Getting the balance right is what keeps you in ketosis day after day.
This calculator sets your macros in a fixed order:
- Calorie target — your maintenance calories (BMR × activity) adjusted for your goal, with a 1,200-calorie floor.
- Net carbs — capped at your chosen limit (20, 30, or 50 g).
- Protein — about 1.6 g per kg of body weight to protect muscle.
- Fat — fills whatever calories remain.
Why fat fills the rest
Once your carb cap and protein target are locked in, every remaining calorie comes from fat. That is why a keto plate looks fat-heavy — fat is simply the fuel that replaces the carbs you have removed. On a strict 20 g plan, fat often supplies 70% or more of your calories.
The bars in the result card show the actual percentage of calories each macro contributes, recalculated from its grams — so you can see at a glance how fat-dominant your day needs to be. Curious how your maintenance calories are derived? See the TDEE calculator.
Net carbs vs total carbs
Keto counts net carbs, not total carbs. Net carbs are the carbohydrates your body actually digests and converts to glucose:
- Net carbs = total carbs − fibre − sugar alcohols
Fibre and most sugar alcohols pass through with little effect on blood sugar, so they do not count against your limit. This means a leafy salad with high total carbs can still be very low in net carbs — one reason keto can include plenty of non-starchy vegetables.
Turning macros into meals
Knowing your numbers is easy; hitting fat, protein, and net carbs every single day is the real challenge. Swoodie tracks all three against your keto target, scans meals and barcodes to log them instantly, and suggests recipes that fit your remaining macros. See the full keto guide to go deeper.
Frequently asked questions
What are keto macros?
Keto macros are the daily split of fat, protein, and carbohydrate that keeps you in ketosis. On a ketogenic diet most of your calories come from fat, protein is set to preserve muscle, and net carbs are kept low — typically 20 to 50 grams a day.
How many carbs can I eat on keto?
Most people enter ketosis at 20–50 grams of net carbs per day. Strict keto uses a 20-gram limit, while a more relaxed low-carb approach allows up to 50 grams. This calculator lets you pick 20, 30, or 50 grams.
What are net carbs?
Net carbs are the carbohydrates your body actually digests for energy. You calculate them by taking total carbs and subtracting fibre and sugar alcohols, which have little to no effect on blood sugar.
Why is fat so high on keto?
On keto, fat replaces carbohydrate as your main fuel. Once your carb limit and protein target are set, fat fills the rest of your calorie budget — that is why fat makes up the largest share of a keto plate.
How much protein should I eat on keto?
A common target is around 1.6 grams of protein per kilogram of body weight, enough to protect muscle without crowding out fat. Very high protein can be turned into glucose, so keto keeps protein moderate rather than maximal.
This tool provides general estimates for healthy adults and is not medical advice. Talk to your doctor before starting keto, especially if you have diabetes, take medication, or have a medical condition.