Bread calories, per slice and per 100 g
White bread is 266 calories per 100 g and whole wheat is 252. USDA puts a slice at 32 g — about 81 calories. The per-100-g figures are close enough to be a rounding error; the thing that actually decides your number is how thick the slice is.
| Per 100 g | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|
| White, commercially prepared | 266 | 8.8 g | 49.4 g | 3.3 g |
| Whole-wheat, commercially prepared | 252 | 12.4 g | 42.7 g | 3.5 g |
Slice weight is the whole game
USDA carries several slice sizes for white bread, from a 9 g thin slice with the crust cut off upward. Supermarket bread ranges from about 25 g for a thin sandwich slice to over 45 g for thick-cut or artisan. That is 66 to 120 calories for "a slice of bread" — and two slices a day at the wrong end of that range is 108 calories you did not log.
The loaf tells you. Divide the total weight on the packet by the slice count once, write it down, and you never have to think about it again.
| Serving | Weight | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|---|
| 1 slice thin, crust not eaten | 9 g | 24 | 0.8 g | 4.4 g | 0.3 g |
| 1 slice crust not eaten | 12 g | 32 | 1.1 g | 5.9 g | 0.4 g |
| 1 slice, very thin | 15 g | 40 | 1.3 g | 7.4 g | 0.5 g |
| 1 slice, thin | 20 g | 53 | 1.8 g | 9.9 g | 0.7 g |
| 1 slice | 25 g | 66 | 2.2 g | 12.4 g | 0.8 g |
| 1 oz | 28 g | 75 | 2.5 g | 14.0 g | 0.9 g |
USDA’s white bread slice sizes.
Whole wheat is not a diet food
252 against 266 calories per 100 g — a 5% difference, which no one will ever notice. What whole wheat genuinely has is more protein (12.5 g against 8.9 g per 100 g, a 40% increase) and considerably more fiber. Those are good reasons to prefer it. Weight loss is not one of them.
What goes on it
Two slices of toast is 162 calories. Two tablespoons of peanut butter is 191 — more than the bread. Butter is roughly 100 a tablespoon, and half an avocado is 120. As with almost everything on this site, the base is the small number and the topping is the large one.
Toasting
Toasting drives off water, so toasted bread reads higher per 100 g than the same bread untoasted — USDA carries them as separate records for exactly that reason. The slice has not gained anything. If you are logging by slice rather than by weight, ignore it.
Source: USDA FoodData Central, SR Legacy release 2018-04. Figures are per 100 g as published; serving weights are USDA’s own. Records used: Bread, white, commercially prepared (includes soft bread crumbs) (FDC 174924), Bread, whole-wheat, commercially prepared (FDC 172688).
Common questions
About 81 for a 32 g slice at USDA’s 266 calories per 100 g for white. Real slices range from about 25 g to over 45 g, so 66 to 120 calories.
Only just — 252 against 266 per 100 g, about 5%. Its real advantages are protein, 12.5 g against 8.9 g per 100 g, and fiber.
Not per slice. Toasting removes water, so toasted bread reads higher per 100 g, but nothing was added to the slice.
Divide the loaf weight on the packet by the number of slices. Do it once and write it down.
Compare it with
| Food | Per 100 g | Protein | The page |
|---|---|---|---|
| Potato | 93 kcal | 2.5 g | Identical to sweet potato on calories |
| Sweet potato | 90 kcal | 2.0 g | By size, and what it actually beats potato on |
| Oats | 379 dry | 13.2 g | Dry against cooked — a 5.3× difference |
All twenty-four are on the food macros index.
Log it without doing this arithmetic
Scan the barcode or weigh it in grams and EatSleepRep does the conversion. The scanner is free forever, there are no ads, and every entry exports as CSV whenever you want it.