How many carbs can you eat on keto a day?
Most ketogenic diets keep total carbs under 50 grams a day, according to Harvard's Nutrition Source, and stricter plans go as low as 20 grams. Popular keto plans set carbs at about 5% to 10% of daily calories. On a 2,000-calorie diet, Harvard's example works out to about 40 grams of carbs.
Ask three people how many carbs they eat on keto and you might hear "basically zero," "under 50," and "only net carbs count." Then a snack bar says "2 g net carbs" next to a much bigger total. The good news? The range is well described, and a few terms make it simple.
What is a keto diet, exactly?
A ketogenic (keto) diet is a very low-carb, high-fat way of eating. When stored glucose runs low, Harvard explains, the liver makes ketone bodies from fat. The body can use them for fuel.
When ketones build up in the blood, that is called ketosis.
Harvard's Nutrition Source also points out that there is no single "standard" keto diet. Different plans set slightly different targets. But they all cut carbs hard, and they all land in a similar zone.
How many carbs on keto is the usual range?
Harvard's Nutrition Source gives a clear range. A ketogenic diet:
- Typically keeps total carbs under 50 grams a day.
- Can go as low as 20 grams a day.
Popular keto resources suggest this split of daily calories:
| Macro | Share of calories |
|---|---|
| Fat | 70% to 80% |
| Protein | 10% to 20% |
| Carbohydrate | 5% to 10% |
Harvard gives an example. On a 2,000-calorie diet, that works out to about 165 g of fat, 40 g of carbs, and 75 g of protein.
For context, the Institute of Medicine sets the RDA for carbs at 130 g a day for adults. Its normal range is 45% to 65% of calories. Keto sits far below that on purpose. Our guide on how many carbs per day covers the standard numbers.
How do you find your own keto carb number?
Take 5% and 10% of your daily calories, then divide by 4. That gives your carb range in grams, because each gram of carb has 4 calories.
- Find your daily calories with our TDEE calculator.
- Multiply by 0.05 and by 0.10.
- Divide each number by 4.
Here are two sample people, run through the Mifflin-St Jeor equation our calculators use, with the site's 20% weight-loss adjustment. They are examples only.
A woman, 170 lb (77 kg), 5 ft 4 in (163 cm), age 40, lightly active
- Weight-loss calories: about 1,570 a day.
- 5% to 10% of 1,570 = about 20 to 39 g of carbs a day.
A man, 210 lb (95 kg), 5 ft 10 in (178 cm), age 40, lightly active
- Weight-loss calories: about 2,060 a day.
- 5% to 10% of 2,060 = about 26 to 52 g of carbs a day.
What I find interesting is that the man's top number edges past 50 g. That's why Harvard's simple rule makes a handy check. Stay under 50 g, and go lower if your plan calls for it.
Our keto calculator lets you pick a daily limit of 20, 30, or 50 g. Then it builds your protein and fat around it.
Should you count net carbs or total carbs on keto?
It depends on your plan, but total carbs is the simpler and stricter choice. Net carbs are easy to get wrong.
- Total carbs is the full carbohydrate number on a food label.
- Net carbs is total carbs minus fiber (and sometimes minus sugar alcohols).
Fiber is a carb your body can't fully digest. So some keto plans don't count it. That's the idea behind net carbs.
Here's the catch. Harvard notes that "net carbs" and "impact carbs" are unregulated terms created by food companies. The math is not exact, because some sugar alcohols can still add calories and raise blood sugar. Even within the keto community, people debate whether to use net carbs at all.
My take, based on what I've seen in the research: if you are new to keto, count total carbs. If you count net carbs, do it with whole foods like vegetables and nuts. Skip the "low net carb" snack bars.
What do 20 to 40 g of carbs look like in real food?
A full day of eggs, chicken, salmon, vegetables, avocado, nuts, and berries can come in at about 40 g of total carbs. Here is one sample day built from USDA FoodData Central values. It is one example, not a meal plan.
| Meal | Food | Total carbs | Fiber |
|---|---|---|---|
| Breakfast | 2 large eggs (100 g) | 0.7 g | 0 g |
| Breakfast | 1 cup raw spinach (30 g) | 1.1 g | 0.7 g |
| Breakfast | 1 oz cheddar (28 g) | 0.9 g | 0 g |
| Lunch | 4 oz roast chicken breast (113 g) | 0 g | 0 g |
| Lunch | 1 cup cooked broccoli (156 g) | 11.2 g | 5.1 g |
| Lunch | 3.5 oz avocado (100 g) | 8.5 g | 6.7 g |
| Snack | 1 oz almonds (28 g) | 6.1 g | 3.5 g |
| Dinner | 5 oz baked salmon (142 g) | 0 g | 0 g |
| Dinner | 1 cup raw cauliflower (107 g) | 5.3 g | 2.1 g |
| Dessert | ½ cup strawberries (76 g) | 5.8 g | 1.5 g |
| Total | about 40 g | about 20 g |
That's about 40 g of total carbs, or about 20 g of net carbs. Same food, two very different numbers. This is exactly why it helps to know which one your plan uses.
It also shows something encouraging. This day still reaches about 20 g of fiber. That is short of the 25 g adequate intake for women 19 to 50 and the 38 g for men. But it's far better than a keto day built only on meat and cheese. Our fiber calculator shows your own target.
Where do the carbs hide?
Grains, fruit, and starchy foods use up a keto budget fast. Here are a few foods from the same USDA data:
- 1 cup (158 g) cooked white rice: 45 g carbs
- 1 medium (118 g) banana: 27 g carbs
- 1 slice (32 g) whole-wheat bread: 14 g carbs
One cup of rice alone would use up most of a 50 g day. Harvard lists grains, starchy vegetables, fruit juice, most fruits, beans, and lentils as foods that keto plans limit or skip.
How much protein should you eat on keto?
Keto keeps protein moderate, usually 10% to 20% of calories. Harvard explains why. Your body can turn some protein into glucose, so very high protein may make ketosis harder.
That creates a real trade-off if you also want to keep muscle while losing weight. Our keto calculator takes its protein number from our protein calculator, which can land above 20% of calories. That choice puts keeping muscle first.
Neither approach is "wrong." They just serve different goals. A registered dietitian can help you balance them.
Can you eat out on keto?
Yes. Many chains now list protein-heavy items with very few carbs. From the chain data on our site:
- Chipotle: High Protein Cup, Chicken (4 oz): 0 g carbs, 32 g protein, 180 calories.
- Chick-fil-A: 8 ct Grilled Nuggets: 1 g carbs, 25 g protein, 130 calories. The Hash Brown Scramble Bowl with Grilled Filet, no hash browns: 2 g carbs, 29 g protein.
- Subway: Grilled Chicken Protein Bowl: 12 g carbs, 48 g protein, 620 calories.
- Starbucks: Bacon & Gruyère Egg Bites: 9 g carbs, 19 g protein.
Watch the sauces and sides. They are where carbs sneak back in.
What should you know before starting keto?
Expect a rough first stretch, and know the long-term concerns. Harvard lists common early symptoms of cutting carbs this low:
- hunger and tiredness
- low mood and irritability
- constipation and headaches
- "brain fog"
These can last days to weeks, and they may ease with time.
Harvard also flags possible long-term concerns. These include kidney stones, bone loss, and higher uric acid (linked to gout). There can also be gaps in fiber, B vitamins, iron, magnesium, and zinc. Eating a wide mix of allowed foods helps.
Talk to your doctor first if this applies to you
If you have type 1 or type 2 diabetes, kidney or liver disease, a history of an eating disorder, or you are pregnant or breastfeeding, talk to your doctor or a registered dietitian before trying keto. This also matters if you take any medicines, especially ones that lower blood sugar.
The bottom line on how many carbs on keto
Most keto plans keep you under 50 g of total carbs a day, and stricter ones go down to about 20 g. In percentage terms, that's roughly 5% to 10% of your calories.
Pick a plan. Decide whether you're counting total or net carbs. Then build your day around protein, low-starch vegetables, and healthy fats. Try our keto calculator to get your own starting number. You've got this.