Energy
lower quarter238 kcalthis record per 100 g
- Corpus median
- 277 kcal
- Middle 50%
- 262–299 kcal
Based on 104 records reporting energy.
Breads & baked goodshigher variability
Bread, onion calories: 74 per 1 medium or regular slice (31 g)
This exact USDA record reports 74 calories for 1 medium or regular slice (31 g). That answer belongs to this description and weight; it is not a universal value for every meal that shares the name.
Quick facts
1 medium or regular slice · 31 g
- Calories
- 74 kcal
- Protein
- 2.7 g
- Carbohydrate
- 13.7 g
- Total fat
- 0.9 g
- Fiber
- 0.5 g
- Sodium
- 149 mg
Portion calculator
Estimate your portion
Choose a source measure or enter the weight you ate.
Estimated for 1 medium or regular slice · 31 g
74calories
Bread, onion
- Protein
- 2.7 g
- Carbs
- 13.7 g
- Fat
- 0.9 g
— means the source has no value available.
These values scale the selected reference food by weight. Ingredients, preparation, and portion size can change your meal’s estimate.
Nutrition facts, household measures, preparation notes and USDA sources
The editorial read
The useful answer has a weight, a composition, and an identity
Portion: the cited record reports about 74 calories for 1 medium or regular slice at 31 grams. On a fixed-weight basis, the same record contains 238 calories per 100 grams. The first number answers a portion question; the second answers a concentration question.
Composition: that source amount also reports 2.7 g protein, 0.5 g fiber, and 149 mg sodium. Read those values together: a calorie total by itself cannot describe the nutrient profile.
Identity: the largest listed formulation input is flour, bread, white, enriched, unbleached, representing 50.7% of the record’s listed input weight. The record contains 9 source-input rows in all. These are provenance for a standardized calculation, not a recipe for your plate.
The source calls its underlying survey portion “Quantity not specified,” but it separately lists 1 medium or regular slice at the identical weight. We use the familiar household label here without changing the source calculation.
The household measures attached to this record span roughly 11–102 calories across the listed portions. That is a set of scaled examples—not a confidence interval, a recommendation, or a claim about the full universe of recipes.
Calculated from the smallest and largest usable household measures listed by USDA for this exact FNDDS record; not a confidence interval.
Record-specific decision brief
What the numbers say—and what choice still belongs to you
This analysis belongs to USDA FDC 2707633: “Bread, onion.” It separates gram-weight arithmetic, corpus context, label signals, and record selection so one number does not have to answer four different questions.
01 · Portion arithmetic
Three weights, one fixed composition
For FDC 2707633, each row multiplies the published per-100-gram values by its stated weight. “1 cubic inch” through “1 large or thick slice” are weight scenarios: named measures come from USDA, while percentage labels are transparent arithmetic.
| Scenario | Weight | Energy | Protein | Fiber | Sodium |
|---|---|---|---|---|---|
| 1 cubic inchUSDA-listed household measure | 4.7 g | 11 kcal | 0.4 g | 0.1 g | 23 mg |
| 1 medium or regular sliceUSDA-listed household measure | 31 g | 74 kcal | 2.7 g | 0.5 g | 149 mg |
| 1 large or thick sliceUSDA-listed household measure | 43 g | 102 kcal | 3.8 g | 0.7 g | 207 mg |
02 · Fixed-weight context
Where 100 grams sits inside Yeast breads
The comparison set contains 104 exact records in the Yeast breads USDA category. Here, “lower quarter” describes FDC 2707633’s energy position in that corpus—not nutritional quality, desirability, or a health rating.
Protein
middle half8.8 gthis record per 100 g
- Corpus median
- 9.8 g
- Middle 50%
- 8.8–11.4 g
Based on 104 records reporting protein.
Dietary fiber
lower quarter1.7 gthis record per 100 g
- Corpus median
- 4 g
- Middle 50%
- 2.3–6.3 g
Based on 104 records reporting dietary fiber.
Sodium
middle half482 mgthis record per 100 g
- Corpus median
- 495 mg
- Middle 50%
- 447–585 mg
Based on 104 records reporting sodium.
03 · FDA label lens
The strongest strength-side and tradeoff-side signals
At FDC 2707633’s 31 g reference weight, the largest strength-side percentage among the nutrients evaluated here is Iron; the larger tradeoff-side percentage is Sodium. Percentages use FDA label Daily Values, whose general “high” guide begins at 20% Daily Value. This is not an overall score or a personalized target.
Strength-side signals
Iron1 mg
≈ 5% DV. This does not cross the FDA’s 20% ‘high’ guide.
Tradeoff-side signals
Sodium149 mg
≈ 6% DV. This does not cross the FDA’s 20% ‘high’ guide.
Saturated fat0.3 g
≈ 2% DV. This does not cross the FDA’s 20% ‘high’ guide.
04 · Highest-impact checks
The three levers most worth resolving first
For “Bread, onion,” the first-pass checks follow the evidence actually published: its named weights, the FDC 2707634 alternative, and its source-formulation identity.
- 01
Listed portion span: 1 cubic inch to 1 large or thick slice
USDA assigns those measures 4.7 g and 43 g. At this record’s fixed composition, scaled energy moves from 11 kcal to 102 kcal.
- 02
Record choice: compare with FDC 2707634
At an equal 100 g, this record has 24 kcal less calories than “Bread, onion, toasted.” That is a record-level contrast; it does not identify which ingredient caused the difference.
- 03
Formulation anchor: Flour, bread, white, enriched, unbleached
The source formulation has 9 input rows; Flour, bread, white, enriched, unbleached supplies 50.7% of listed input weight. Those are standardized formulation inputs, not final plated percentages.
05 · Exact-record choice
Select by literal evidence, not the shortest name
Keep this record when “onion” fits. Inspect FDC 2707634 when “onion; toasted” is the more literal description of the food and preparation.
Keep this profile when these fields fit
Bread, onion
- Exact source wording
- “Bread, onion”
- Source identity
- USDA FDC 2707633 · FNDDS 51121110
- Named qualifiers
- onion
- Source inputs unique in this pair
- Beverages, water, tap, drinking · Milk, NFS · Salt, table
Inspect this alternative when its fields fit better
Bread, onion, toasted
- Exact source wording
- “Bread, onion, toasted”
- Source identity
- USDA FDC 2707634 · FNDDS 51121120
- Named qualifiers
- onion · toasted
- Source inputs unique in this pair
- Bread, onion
Choose the closest description
Which USDA record fits your meal?
Treat the long description as data. The phrases doing the most work here are “onion”. Match those details first; then compare the database weight with the amount you mean.
On smaller screens, focus a nutrition table and scroll horizontally to read every column.
| Exact record | Source serving | Calories / 100 g | Protein / 100 g | Fat / 100 g | Fiber / 100 g | Sodium / 100 g |
|---|---|---|---|---|---|---|
| This recordBread, onion | 31 g74 kcal | 238 kcal | 8.8 g | 3 g | 1.7 g | 482 mg |
| Bread, onion, toasted | 28 g73 kcal | 262 kcal | 9.7 g | 3.2 g | 1.9 g | 530 mg |
| Bread, rice | 28 g69 kcal | 248 kcal | 4.3 g | 5.2 g | 4.3 g | 447 mg |
| Bread, pumpernickel | 32 g80 kcal | 250 kcal | 8.7 g | 3.1 g | 6.5 g | 596 mg |
| Bread, black | 28 g70 kcal | 250 kcal | 8.7 g | 3.1 g | 6.5 g | 596 mg |
| Bread, cinnamon | 28 g71 kcal | 253 kcal | 7.1 g | 5.3 g | 3.5 g | 388 mg |
| Bread, vegetable | 44 g114 kcal | 259 kcal | 9.7 g | 3.3 g | 1.8 g | 532 mg |
How to compare FDC 2707633: its source amount is 31 g; every 100-gram column removes portion size from the record-to-record comparison. Neither denominator determines your plate’s weight or recipe.
Household measures
Compare listed portions
For FDC 2707633, the 6 displayed measures scale the same source composition by gram weight; rounding changes presentation, not the underlying ratio.
1 small or thin/very thin slice
57 kcal
24 g
1 medium or regular slice
74 kcal
31 g
1 large or thick slice
102 kcal
43 g
1 slice, crust not eaten
33 kcal
14 g
1 slice, snack-size
24 kcal
10 g
1 cubic inch
11 kcal
5 g
At a glance
Nutrient signals in the source amount
For FDC 2707633, Sodium is the largest displayed non-protein Daily Value signal. Read the set as label context—not a personalized score.
Sodium
149.4 mg≈ 7% Daily ValueIron
1 mg≈ 5% Daily ValueThe percentages above apply to FDC 2707633’s 31 g reference amount. FDA Daily Values are general label references, not individualized energy or medical targets. Read the FDA explanation ↗
Why FDC 2707633 has no protein percentage here: Feast reports 2.7 g, but does not present grams divided by 50 as FDA protein %DV; applicable label rules account for protein quality and regulatory context.
Nutrition facts
Compare the source serving with 100 grams
Values are rounded for readability. The source serving is 31 g.
| Nutrient | Amount | Approx. % Daily Value |
|---|---|---|
| Calories | 74 kcal 238 kcal | Not established Not established |
| Protein | 2.7 g 8.8 g | Not shown Not shown |
| Carbohydrate | 13.7 g 44.3 g | 5% 16% |
| Total fat | 0.9 g 3 g | 1% 4% |
| Dietary fiber | 0.5 g 1.7 g | 2% 6% |
| Sugars | 1 g 3.3 g | Not established Not established |
| Sodium | 149.4 mg 482 mg | 6% 21% |
| Saturated fat | 0.3 g 1 g | 2% 5% |
| Monounsaturated Fat | 0.2 g 0.7 g | Not established Not established |
| Polyunsaturated Fat | 0.2 g 0.7 g | Not established Not established |
| Cholesterol | 1.2 mg 4 mg | 0% 1% |
| Potassium | 38.4 mg 124 mg | 1% 3% |
| Calcium | 11.2 mg 36 mg | 1% 3% |
| Iron | 1 mg 3.1 mg | 5% 17% |
| Magnesium | 7.4 mg 24 mg | 2% 6% |
| Vitamin C | 0.3 mg 0.9 mg | 0% 1% |
| Vitamin D | 0.1 µg 0.2 µg | 0% 1% |
| Vitamin A | 5.3 µg 17 µg | 1% 2% |
| Caffeine | 0 mg 0 mg | Not established Not established |
| Alcohol | 0 g 0 g | Not established Not established |
| Water | 13.1 g 42.2 g | Not established Not established |
For FDC 2707633, approximate percentages divide the displayed 31 g amount by FDA label Daily Values; they are not personalized targets. “Not established” means FDA sets no Daily Value for that row. Protein %DV remains unshown because adult-label use depends on regulatory context.
Inside the source record
Source formulation behind this USDA record
USDA links FDC 2707633 to 9 source inputs totaling 809.9 g in its standardized formulation. Publishing that exact provenance makes “Bread, onion” inspectable beside similarly named records.
How to read this
9 listed components
The largest listed inputs by source weight are Flour, bread, white, enriched, unbleached, Milk, NFS, Onions, raw. The order and weights below come from the standardized USDA formulation, so they offer context for this exact database entry.
809.9 g total listed input weight across the formulation.
| # | USDA input | Listed amount | Input weight | Share of listed input weight |
|---|---|---|---|---|
| 1 | Beverages, water, tap, drinkingUSDA ingredient 14411 · encyclopedia page available | 0.5 C | 118.5 g | 14.6% |
| 2 | Milk, NFSUSDA ingredient 11100000 · encyclopedia page available | 0.5 C | 122 g | 15.1% |
| 3 | Salt, tableUSDA ingredient 2047 · encyclopedia page available | 1.5 TS | 9 g | 1.1% |
| 4 | Sugars, granulatedUSDA ingredient 19335 · encyclopedia page available | 1 TB | 12.5 g | 1.5% |
| 5 | Butter, stick, saltedUSDA ingredient 1001 · encyclopedia page available | 0.5 TB | 7 g | 0.9% |
| 6 | Shortening, vegetable, household, compositeUSDA ingredient 4615 · encyclopedia page available | 6.41 GM | 6.4 g | 0.8% |
| 7 | Leavening agents, yeast, baker's, active dryUSDA ingredient 18375 · encyclopedia page available | 0.5 | 3.5 g | 0.4% |
| 8 | Flour, bread, white, enriched, unbleachedUSDA ingredient 20083 · encyclopedia page available | 3 C | 411 g | 50.7% |
| 9 | Onions, rawUSDA ingredient 11282 · encyclopedia page available | 120 GM | 120 g | 14.8% |
USDA shorthand in this evidence
- NFS means “not further specified.” The record intentionally leaves the exact subtype, size, or preparation unresolved.
Exact-record context
What makes this USDA record distinct?
For FDC 2707633, the close-record rule searches the USDA “Yeast breads” category for shared description terms or source inputs. Any surviving pair is compared per 100 grams, so unlike source-serving sizes cannot manufacture the nutrient difference.
This record
Bread, onion
- USDA category
- Yeast breads
- FDC ID
- 2707633
- FNDDS code
- 51121110
Closest inspectable record
Bread, onion, toasted
- USDA category
- Yeast breads
- FDC ID
- 2707634
- FNDDS code
- 51121120
| Nutrient | This record | Comparison record | Difference |
|---|---|---|---|
| Calories | 238 kcal | 262 kcal | −24 kcal |
| Protein | 8.8 g | 9.7 g | −0.9 g |
| Carbohydrate | 44.3 g | 48.7 g | −4.4 g |
| Total fat | 3 g | 3.2 g | −0.3 g |
| Dietary fiber | 1.7 g | 1.9 g | −0.2 g |
| Sodium | 482 mg | 530 mg | −48 mg |
Plain-English read
At the fixed 100-gram basis, this record lists 24 less calories than “Bread, onion, toasted.”
Only this record lists Beverages, water, tap, drinking; Milk, NFS; Salt, table; Sugars, granulated. Only the comparison record lists Bread, onion. Those formulation rows identify different source records; they do not prove which input caused a nutrient difference.
1 of the six displayed differences clears the documented materiality screen. It is a reading aid, not a health rating.
Formulation evidence
The listed formulations differ
The formulation rows differ, but the source data do not isolate which component caused any nutrient difference. Input weights describe the standardized formulation—not final plated proportions.
Listed only in this record: Beverages, water, tap, drinking; Milk, NFS; Salt, table; Sugars, granulated; and 5 more.
Listed only in the comparison: Bread, onion.
Portion evidence
The listed portion sets differ
This record’s reference amount is 31 g; a familiar listed measure is 1 medium or regular slice (31 g).
The comparison record’s reference amount is 28 g; a familiar listed measure is 1 medium or regular slice (28 g).
Use the 100-gram row to compare FDC 2707633 with FDC 2707634 at equal mass; use their 31 g and 28 g source amounts only for portion matching.
Evidence boundary: FDC 2707633 versus FDC 2707634 is a comparison of standardized source records—not a measurement of your meal, an overall food-quality rank, or proof that one input caused a difference.
Review the full yeast breads source category → Read the calculation and selection methodology →
From record to familiar meal
Guides that use this exact USDA record
These 1 guide place “Bread, onion” beside explicitly linked source records; use them to compare preparations without turning FDC 2707633 into a universal recipe.
Uncertainty, made actionable
What can change this estimate?
This is a standardized USDA survey-food profile, not a measurement of every preparation. Actual nutrition can change with item size, recipe or brand, moisture and density, spreads or toppings.
For “Bread, onion,” resolve item size first, then move through the remaining 3 published levers. Unknowns should remain visible rather than expanding every assumption at once.
- 01
item size
When composition is held constant, nutrient totals scale directly with grams. A 20% weight correction produces the same 20% correction to the scaled totals.
- 02
recipe or brand
Prefer a package, menu, or known recipe when it identifies the food more precisely. Otherwise preserve the generic record as an explicit approximation.
- 03
moisture and density
Match the food state before matching the number. Cooking, draining, or added liquid can change grams and concentration even when the food name barely changes.
- 04
spreads or toppings
Check whether the exact source description already includes it. If not, keep the addition separate rather than silently folding it into the base record.
How we estimated this
The arithmetic is simple; the provenance is the point
FDC 2707633 comes from FoodData Central Survey Foods (FNDDS). Its 238 kcal per 100 g becomes 74 kcal at 31 g through nutrient per portion = nutrient per 100 g × portion grams ÷ 100; this page adds no second nutrition estimate.
About the serving label: USDA describes the underlying survey portion as “Quantity not specified.” The separately listed 1 medium or regular slice has the same gram weight, so the familiar label can be shown without changing the calculation.
Data cycle: 2021–2023, published October 31, 2024
FoodData Central ID: 2707633
FNDDS food code: 51121110
The scaling for FDC 2707633 can be exact while the match to “Bread, onion” is wrong. That is why this profile keeps its 31 g weight, 9-row source formulation, and selection uncertainty beside the arithmetic.
Source release October 31, 2024. Review USDA’s data-type documentation ↗ · Read Feast’s full nutrition methodology.