Try around 1/2 inch for an everyday sandwich, 1/2 to 3/4 inch for toast, and 3/4 to 1 inch for French toast. Adjust from there to suit the bread and the meal. A slice needs to hold its filling, fit your toaster, and be comfortable to eat.
Suggested starting sizes
| Use | Starting thickness | Approximate metric size | Adjust if… |
|---|---|---|---|
| Thin toast or crisp serving slices | 1/4 to 3/8 inch | 6 to 10 mm | The crumb tears or won't support the topping |
| Everyday sandwiches | 3/8 to 1/2 inch | 10 to 13 mm | An open crumb or substantial filling needs more support |
| Breakfast toast | 1/2 to 3/4 inch | 13 to 19 mm | You want a softer middle or a lighter, crisper result |
| Open-faced toast | 3/4 to 1 inch | 19 to 25 mm | The topping is heavy or the slice is awkward to eat |
| French toast | 3/4 to 1 inch | 19 to 25 mm | Your recipe specifies a different size or the center cooks unevenly |
These are suggested starting points, with metric sizes rounded for kitchen use. They aren't standardized portions or product-test results. There's overlap because a 1/2-inch slice can work for both a sandwich and toast.
Sandwiches: try a pair before slicing the loaf
Small changes add up when there are two pieces of bread in each sandwich. Start toward the thinner end of the range for a modest filling. Try a little more thickness when the filling needs support.
Bread with large holes may need a different cut from a close-textured pan loaf, even at the same thickness.
On a round loaf, pair neighboring slices. Their outlines are more likely to match than a heel and a piece from the center. Make one sandwich before cutting the rest of the loaf. If each bite feels like too much bread, make the next pair thinner. If it tears as you assemble it, check the crumb and filling as well as the slice size.
Toast: check what fits
Leave enough clearance for the bread to move freely in a pop-up toaster. Don't squeeze a thick slice into a narrow slot. A wide boule can also produce pieces that are too long even at a suitable thickness; cut smaller portions or use a toaster oven that fits them.
Start within the toast range and change one setting at a time. Adjusting thickness, cooking time, and temperature all at once makes a good result harder to repeat.
For open-faced toast, consider how you'll eat it. A thick base may work well with a knife and fork. A thinner piece may be easier to pick up. Use the meal to choose the size, even if your slicer can cut much thicker pieces.
French toast: use the recipe's thickness
Follow the thickness in your recipe when it gives one. Bread type, soaking instructions, and cooking method work together, and changing the cut may call for other adjustments.
If you're choosing a size yourself, begin around 3/4 to 1 inch. Keep the pieces reasonably even so they cook at similar rates. Follow the recipe's doneness guidance, particularly for an egg mixture: a brown surface doesn't establish that the middle is cooked as intended.
Large holes or an unusually firm sourdough crust can affect how the bread works in the recipe. Try a small batch before cutting the whole loaf and adjust the next batch to your preference.
Getting the same thickness twice
Begin with cooled bread on a stable board. Make a first cut that stays in one plane; a slanted face is a poor reference for the next slice. Our sourdough slicing guide covers the technique for whole loaves and smaller portions.
Set the knife aside before measuring a finished slice with a ruler. Look at its side and compare the top, middle, and bottom. If the thickness varies markedly, work on the cutting angle before changing the number you're aiming for. Keep the ruler away from a moving blade.
With a guided slicer, choose and secure the guide position before starting. Leave the adjustment alone while cutting.
When a size works, make a brief note so you can repeat it: "1/2-inch sandwich slices, smaller half-loaf shape." Include the bread type, since the same setting can feel different on a soft pan loaf and crusty sourdough. Label freezer portions by their intended use; our sourdough freezing guide explains how to separate and package them.
Choosing a setting on Bread Pilot
Bread Pilot's product information lists an adjustable range of approximately 1/4 inch to 2 inches. Choose a setting for the meal and check the slice it produces. For ordinary toast, keep the toaster's clearance in mind before using a thick setting.
The guide provides a reference, while the loaf's shape, previous cut angle, and your motion still affect the finished piece. The stated range doesn't guarantee exact slice measurements.
Keechee's labeled thickness illustrations show examples within that range. Use them to understand the adjustment options, and follow your recipe or appliance instructions when choosing what to cut.
See how Bread Pilot works to watch the guide in use.
When to change your slice size
If a thin slice tears, check that the loaf has cooled and the blade is cutting cleanly. The crumb may need a slightly thicker cut to hold together. The narrowest setting won't suit every loaf.
Half an inch is a useful reference for several meals, so keep it if it works. Adjust it for the filling, bread texture, or cooking method when needed. Freezing alone doesn't call for thicker slices; cut for the meal you'll make after thawing or toasting.