How much fiber is in whole wheat bread?
Whole wheat bread has 1.7 g of fiber per 1 slice (28 g) — about 6% of the 28 g Daily Value. That's 6 g of fiber per 100 g.
USDA FoodData Central · commercially prepared · FDC 172688
Fiber by portion
| Portion | Fiber | % DV | Total carbs | Net carbs | Calories |
|---|---|---|---|---|---|
| 1 slice (28 g) | 1.7 g | 6% | 12 g | 10.3 g | 71 |
| 100 g | 6 g | 21% | 42.7 g | 36.7 g | 252 |
| 1 oz (28 g) | 1.7 g | 6% | 12.1 g | 10.4 g | 71 |
% DV against the FDA Daily Value of 28 g of fiber. Net carbs = total carbs − fiber, since fiber isn't digested like other carbs. Values from USDA per-100 g data (FDC 172688, SR Legacy). commercially prepared.
Whole wheat bread has a fiber number that looks better per 100 g than it does in the slice on your plate. At 6 g of fiber per 100 g it reads respectably — but 100 g is roughly three and a half slices, far more bread than a sandwich uses. A single standard slice (28 g) carries only about 1.7 g of fiber, around 6% of the 28 g Daily Value. Two slices, the bread in an actual sandwich, give you closer to 3.4 g, or about 12% of the day. That’s the honest headline: whole wheat is better than white, but a slice is still a small fiber contribution.
Better than white bread — but not magic
The swap from white to whole wheat is a real upgrade, and fiber is the main reason. Whole wheat keeps the bran and germ that refining strips out, and that bran is mostly insoluble fiber — the kind that adds bulk and supports digestive regularity. White bread is milled down to mostly starch, so the whole-grain version genuinely carries more fiber, plus more iron, magnesium, and B vitamins. The catch is scale: because a slice was never a big fiber source to begin with, swapping it only moves you from almost no fiber to a little. The swap helps, it just isn’t going to cover your day. If fiber is the goal, the bread is the base, not the source.
What the small fiber means for carbs
That modest fiber also means the net-carb math barely moves. A slice has about 12 g of total carbs, and subtracting the 1.7 g of fiber leaves roughly 10.3 g of net carbs — almost the same number, because there isn’t much fiber to take off. Unlike beans or lentils, where fiber slices a big chunk out of the total, whole wheat bread stays a carb-forward food whether you read total or net. So treat it for what it is: a fiber-and-whole-grain carbohydrate that beats white bread on the margins, paired with a real fiber source like beans, oats, or vegetables if you want to actually hit the day’s number.
Bread’s protein per slice is just as modest as its fiber — for that side of the picture, see protein in whole wheat bread. And on any packaged loaf, read the label’s fiber line directly, since seed- and grain-packed breads can carry far more than a plain slice.
Packaged bread options, graded
Prefer something off the shelf? Here are the best-graded bread in our catalog — each scored on our transparent Labelgrade. Check the fiber line on each label.
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Labelgrade 81/100 · 6 g fiber · 5 g protein
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Labelgrade 81/100 · 3 g fiber · 3 g protein
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Frequently Asked Questions
How much fiber is in a slice of whole wheat bread?
About 1.7 g of fiber in a standard slice (28 g), from 6 g per 100 g (USDA FDC 172688). The per-100-g figure looks decent, but 100 g is roughly three and a half slices — far more bread than a sandwich uses, so per slice the fiber is modest.
What percent of the daily value for fiber is that?
Only about 6% of the Daily Value per slice, against the FDA's 28 g fiber DV. Two slices in a sandwich get you to roughly 12% — useful, but not a big dent. Bread isn't a major fiber source the way beans or lentils are.
Is the fiber in whole wheat bread soluble or insoluble?
Mostly insoluble. Wheat bran is largely insoluble fiber, which adds bulk and supports digestive regularity — that's the kind of fiber whole wheat keeps that white bread strips away. There's a little soluble fiber too, but the bran's insoluble fiber is the headline.
How do fiber and net carbs work out in whole wheat bread?
A slice has about 12 g total carbs, and subtracting the ~1.7 g of fiber leaves roughly 10.3 g net carbs. Because the fiber per slice is small, it barely dents the carb count — bread stays a carb-forward food whether you read total or net.
Does whole wheat bread really have more fiber than white bread?
Yes, but the gap per slice is small. Whole wheat keeps the bran and germ, so it carries meaningfully more fiber than white — but a slice is still only about 1.7 g. The swap is a genuine upgrade for fiber and micronutrients; it just isn't magic, since a slice was never a big fiber source to begin with.
When was this data last verified?
2026-06-04, against USDA FoodData Central FDC 172688 (Bread, whole-wheat, commercially prepared; SR Legacy). We re-verify reference pages periodically and update when USDA revises its values.
Whole-food values are USDA reference data, not a Labelgrade (that score is for branded packaged products). See our methodology and the carbs & net carbs lane.