How much weight per slice of bread? The comprehensive guide

January 3, 2026 •

4 min read

While a standard slice of commercial white bread in the U.S. typically weighs around 29 grams, a slice of whole-grain bread is often denser and heavier. This significant variance means there is no single answer to the question of how much a slice of bread weighs, as factors like grain type, density, and thickness all play a crucial role.

Quick Summary

A bread slice's weight is determined by its type, density, and thickness. White bread is lighter than denser whole wheat varieties, influencing nutrition calculations and portion sizes.

Key Points

Weight Varies Significantly: The weight of a bread slice is not standard and can differ based on flour type, density, and thickness.
White vs. Whole Wheat: Whole wheat bread slices are typically heavier and denser than white bread slices due to their higher fiber and grain content.
Impact of Ingredients: Additions like seeds, nuts, and higher moisture content contribute to a heavier slice.
Homemade vs. Commercial: Homemade bread is often denser and can have a much higher weight per slice compared to store-bought varieties.
Kitchen Scale is Key: For precise portion control, a digital kitchen scale is the most accurate tool for measuring the weight of a bread slice.
Nutritional Labels are Guides: Manufacturer serving sizes on packaging provide a useful, weight-based reference, which is more reliable than visual estimation.

Why a Slice's Weight Is Not Standard

Unlike an egg or a cup of milk, a slice of bread is not a standardized unit of measure. Its weight is influenced by a complex interplay of ingredients and baking processes. This variation is why simply counting slices can be a flawed method for accurate portion control, especially for those tracking macronutrients or managing dietary restrictions. Understanding the factors that contribute to this weight difference is the first step toward more informed eating habits.

Density and Grain Type

One of the most significant factors affecting a slice's weight is the type of flour used. Whole-grain bread, made from flour that contains the entire grain kernel (bran, germ, and endosperm), is naturally denser than white bread, which is made from refined flour. The bran and germ components in whole grains are packed with fiber, which adds mass. This is why a slice of whole wheat bread almost always weighs more than a similarly-sized slice of white bread. Artisan and rustic loaves, such as dense rye or sourdough, also tend to be heavier per slice than a light, fluffy sandwich loaf.

The Role of Moisture Content

Moisture is a critical ingredient in bread, and its retention significantly impacts the final weight. Dough hydration, or the ratio of water to flour, varies widely between bread recipes. A highly hydrated dough, typical for rustic artisan loaves, can create a bread with an open, airy crumb structure. However, as bread bakes, it loses moisture, and the amount lost can fluctuate depending on factors like baking time and temperature. A fresher loaf will also weigh slightly more than a stale one that has lost more moisture over time.

Thickness and Added Ingredients

The way a loaf is sliced also directly affects the weight of each piece. Commercially produced 'thin-sliced' breads are explicitly designed to have a lower weight and calorie count per serving. In contrast, thick-cut loaves or hand-sliced homemade bread will result in heavier, larger slices. Furthermore, the inclusion of extra ingredients, such as nuts, seeds, and dried fruits, will add additional weight. For example, a slice of multigrain bread laden with sunflower seeds and flaxseed will be substantially heavier than a plain white slice of the same dimensions.

Common Bread Types and Their Slice Weights

To give a practical idea of how weight can vary, consider the following examples based on nutritional data from commercial products. These are approximations, and actual weights can differ by brand.

White Bread: Around 25–29 grams per slice. This reflects its lower density and refined flour composition.
Whole Wheat Bread: Around 33–43 grams per slice. This heavier weight comes from the inclusion of the entire grain kernel.
Sourdough Bread: Around 32 grams per slice. The density can vary based on the flour used, but it's typically heavier than standard white bread.
Sprouted Grain Bread: Around 34 grams per slice. Sprouted breads like Ezekiel 4:9 often have a dense, compact crumb, contributing to a higher weight.
Artisan/Homemade Bread: Can range widely, often heavier than commercial bread due to a denser crumb. One report suggests homemade slices can be 40–75 grams.

Comparison of Popular Bread Weights


Bread Type	Average Weight per Slice (grams)	Notes
White Bread	25–29g	Lighter, made with refined flour
Whole Wheat Bread	33–43g	Denser, higher in fiber and nutrients
Sourdough Bread	~32g	Weight can vary, often denser than white
Sprouted Grain Bread	~34g	Compact, nutrient-dense loaf
Thin-Sliced Varieties	~28g	Intentionally cut smaller for lower calories
UK Average (Medium Slice)	~38g	A general average, can vary by brand

How to Accurately Determine Slice Weight

For anyone on a specific diet plan, counting slices is an imprecise method. The most reliable way to measure your portion is by using a kitchen scale. This ensures that you are consuming the exact amount of food you intend to, regardless of a slice's density or thickness. Simply place the slice on the scale, and the precise weight in grams or ounces will be displayed. This eliminates guesswork and provides peace of mind for accurate nutritional tracking. For an authoritative source on how food manufacturers determine serving sizes and why it's a useful reference, see this Food Labeling guide from the FDA.

Conclusion: Knowing Your Loaf

The weight per slice of bread is not a fixed measurement. It is a dynamic variable affected by the type of flour, grain density, added ingredients, and the slicing process. Whether you're making a simple sandwich or meticulously managing your macros, being aware of these differences is crucial. The best approach for accuracy is to rely on a kitchen scale rather than making assumptions based on visual size. By understanding your bread, you can make more informed dietary choices and enjoy your meals with confidence.

Best Practices for Bread Portioning

Use a digital kitchen scale: This is the most accurate method for portion control and nutrition tracking.
Read the nutrition label: The label will provide the weight for the designated serving size, typically 1 or 2 slices.
Consider the type of bread: Understand that whole-grain and artisan breads are naturally heavier than standard white bread.
Factor in add-ins: Ingredients like seeds, nuts, and dried fruit increase the overall weight and caloric density of a slice.
Be consistent with your slicing: If you are cutting your own loaf, try to maintain a uniform thickness for predictable portion sizes.
Account for freshness: A fresh loaf retains more moisture and will weigh slightly more than an older, staler one.

Frequently Asked Questions

A standard slice of commercial white bread in the U.S. typically weighs about 29 grams, or roughly 1 ounce. Weights can vary slightly by brand and thickness.

Whole wheat bread is heavier because it is made from the entire grain kernel, including the fibrous bran and germ, which are removed during the refining process for white flour. This results in a denser, more nutrient-rich, and heavier slice.

Yes, toasting bread causes it to lose moisture, leading to a reduction in its overall weight. The longer and crispier the toast, the more weight it loses.

The most accurate way to measure the weight of a bread slice at home is by using a digital kitchen scale. This eliminates the guesswork of relying on inconsistent visual sizes.

Yes, homemade bread slices are often heavier than their store-bought counterparts. This is because home-baked loaves are frequently denser and sliced thicker, with commercial loaves engineered for a lighter, softer texture.

The thickness of slices depends on the manufacturer's slicing setting or a home baker's preference. 'Thin-sliced' bread products are intentionally cut smaller to provide a lower calorie count per slice, appealing to calorie-conscious consumers.

Not always. Some nutrition labels list a serving size as two slices, especially for lighter or 'thin-sliced' bread. Always check the label to confirm the weight and number of slices per serving.