How many carbs are in lentils?
Lentils has 19.9 g of total carbs per 1/2 cup cooked (99 g) — about 12.1 g net carbs after 7.8 g of fiber. That's 20.1 g of carbs per 100 g, roughly 7% of the 275 g Daily Value.
USDA FoodData Central · cooked, boiled · FDC 172421
Carbs by portion
| Portion | Total carbs | Net carbs | Fiber | Sugar | Calories |
|---|---|---|---|---|---|
| 1/2 cup cooked (99 g) | 19.9 g | 12.1 g | 7.8 g | 1.8 g | 115 |
| 100 g | 20.1 g | 12.2 g | 7.9 g | 1.8 g | 116 |
| 1 oz (28 g) | 5.7 g | 3.5 g | 2.2 g | 0.5 g | 33 |
Net carbs = total carbs − fiber (the carbs that raise blood sugar, used in keto/low-carb tracking). Values computed from USDA per-100 g data (FDC 172421, SR Legacy). cooked, boiled.
Lentils carry a total carb number that overstates how they actually eat. A 1/2-cup serving of cooked lentils (99 g) has about 20 g of total carbohydrate — but nearly 8 g of that is fiber, which your body doesn’t digest into blood sugar. Subtract it and the net carbs drop to roughly 12 g, the figure that matters for low-carb and diabetes tracking. Per 100 g the numbers are 20.1 g total carbs, 7.9 g fiber, leaving 12.2 g net — a remarkably low ratio for a starchy-tasting food.
Why net carbs are far below the total
Net carbs are total carbs minus fiber, and lentils have one of the highest fiber shares of any everyday legume — close to 40% of their carbohydrate is fiber. That’s the indigestible part that passes straight through without becoming blood sugar, so while the total reads ~20 g per 1/2 cup, the digestible load your body actually contends with is only about 12 g. This is the cleanest example of “beans aren’t as carby as they look”: almost every legume beats a refined starch on net carbs, but lentils do it by the widest margin, because so much of their carbohydrate is fiber rather than usable starch. There’s very little sugar in them either — under 2 g per 1/2 cup — so the count is mostly slow starch, heavily blunted by fiber.
What this means for keto, low-carb, and blood sugar
For keto, lentils are borderline — at ~12 g net per 1/2 cup, a real portion would eat most of a strict 20 g budget, so they’re a small-serving food at that level. But on a moderate low-carb plan they’re one of the best legume choices precisely because the fiber pulls net carbs lower than most beans, and you get strong protein in the bargain. The blood-sugar story is where lentils genuinely shine: that very high fiber load makes them one of the lowest-glycemic carbohydrates you can eat, with a slow, gentle rise rather than a spike. Combined with their protein, that’s why lentils are repeatedly singled out as a diabetic-friendly carbohydrate — steady energy, low glycemic impact, and a net-carb number well under what the total suggests.
Lentils are also one of the better plant proteins, so the carb count is only half the label — see protein in lentils for the rest. And for any packaged lentil product you’re tracking, check its own carb and fiber lines, since net carbs depend on both.
Frequently Asked Questions
How many carbs are in 1/2 cup of cooked lentils?
About 20 g of total carbohydrate in a 1/2-cup serving of cooked lentils (99 g), which is 20.1 g per 100 g (USDA FDC 172421). Nearly 8 g of that total is fiber, so the net carbs that count for low-carb eating are much lower.
What are the net carbs in lentils?
Roughly 12 g net carbs per 1/2 cup — total carbs (~20 g) minus the ~7.8 g of fiber. Fiber isn't digested into blood sugar, so net carbs subtract it out. Lentils have one of the highest fiber shares of any legume — close to 40% of their carbohydrate is fiber — which is why net carbs land so far below the total.
Are lentils keto or low-carb?
Borderline on keto, good on low-carb — net carbs decide it. At ~12 g net per 1/2 cup, lentils are too high for a strict 20 g keto day in quantity, but they're one of the better legume fits for a moderate low-carb plan because the fiber pulls the net number down further than most beans. Count the net carbs, not the total.
Do lentils spike blood sugar?
No — lentils are one of the lowest-glycemic carbohydrates around. The very high fiber content slows digestion dramatically, so blood sugar rises slowly and gently rather than spiking. That low glycemic response, plus their protein, makes lentils a well-regarded choice for steady energy and diabetic-friendly eating.
How much fiber is in lentils?
About 7.8 g per 1/2 cup (7.9 g per 100 g) — a big chunk of a day's worth from one serving. That fiber is the whole story: it's what makes net carbs (~12 g) so much lower than total carbs (~20 g), and what gives lentils their low glycemic index.
When was this data last verified?
2026-06-04, against USDA FoodData Central FDC 172421 (Lentils, mature seeds, cooked, boiled, without salt; SR Legacy). We re-verify reference pages periodically and update when USDA revises the entry.
Whole-food values are USDA reference data, not a Labelgrade (that score is for branded packaged products). See our methodology and the macro calculator to turn this into a daily target.