Portions and label reading
100 g, portions and counts: a calculation guide
How much is an item, slice, handful or bowl? Separate the 100 g basis from actual edible amounts and apply the calculation.
How to use this guide
Common basis and actual serving
100 g is a common comparison basis, not automatically one item, slice, handful or bowl. Calculate apple, banana, bread and almonds from actual edible weights.
A simple calculation method
A serving value is the recorded per-100 g value multiplied by edible grams / 100. At 50 g use half the recorded value. This formula cannot create a missing measurement.
Why counts and volume vary
Fruit size, bread thickness and bowl volume vary. Milliliters measure volume and grams measure weight; do not equate them without density information. Check sourced portion examples against your own weighing.
Recorded values of selected foods
Check preparation in each food name and provenance in the last column.
| Food record | Energy (kcal) | Source |
|---|---|---|
| Apple | 52 kcal | USDA |
| Banana | 89 kcal | USDA |
| Whole-wheat bread | 254 kcal | USDA (12/2025) |
| Almonds | 579 kcal | USDA (12/2025) |
| Plain yogurt (milk type unspecified) | 63 kcal | USDA (12/2025) |
Calculate your own serving
Enter edible grams. Calculations use the selected record’s per-100 g measurements.
Energy
52 kcal
Measurement × grams / 100. Missing data is not zero; this is not a recommended intake.
Questions about this guide
100 g is a common comparison basis, not automatically one item, slice, handful or bowl. Calculate apple, banana, bread and almonds from actual edible weights.
A serving value is the recorded per-100 g value multiplied by edible grams / 100. At 50 g use half the recorded value. This formula cannot create a missing measurement.
Fruit size, bread thickness and bowl volume vary. Milliliters measure volume and grams measure weight; do not equate them without density information. Check sourced portion examples against your own weighing.