First of all a statement: It is not easy to cut bread with an ordinary kitchen knife, the blade is too small, it does not allow to cut a bread beyond a baguette, and its small handle does not ensure a good grip.
You really need a specific knife for that, and which has, if possible, the following characteristics.
1) A serrated bladeThat is to say with teeth, we often say "saw knife", as opposed to a smooth blade, which allows an easier cutting of the bread.
You will sometimes read, here or there, that you should not "tear the bread crumb" with a serrated blade, but this is nonsense.
2) A long bladeThis is the main defect of bad bread knives, their blade, although serrated, is not long enough to allow a good cutting. With a long blade, your gesture will be more ample, therefore easier, and the cut more regular.
3) A wide handleIt is absolutely necessary that you have a good grip on your knife, so that its handle is comfortable and well adapted to the size of your hand.
4) Practical materialsIt is not an obligation, but your bread knife must be easy to use and maintain, which in my opinion implies both a stainless steel blade and an abs plastic handle or equivalent that does not fear water.
With all these criteria, it is quite simple to find the ideal knife, the choice is quite vast fortunately.
To make a long story short, the main defect you will encounter is a blade that is too short. I advise you to opt for a blade of 10 inches (25 cm) minimum.
You will easily find a lot of bread knives with a 8 inches (20 cm) blade, which certainly cut, but are much less efficient than a 25 cm blade.
The trick I suggest is to look for, or go to a professional store, and choose what they call a "sponge knife", which is a saw knife with all the criteria we just mentioned and a 11 inches (28 cm) blade.
You will be delighted with its efficiency, to easily cut from the smallest to the largest loaf, and to make even slices.
The next time you go to your bakery, look at the knife that the sales team uses to cut the bread for the customers, it is exactly this model.
To sum up: For your bread knife, you need a stainless, long (10 inches (25 cm) minimum) and serrated blade.