Homemade bread sometimes seems to have a mind of its own. The same recipe, made the exact same way, can come out completely differently every time. If you substitute bread flour for all-purpose flour, you can definitely expect a different dough. Bread flour is heavier and less fine than all-purpose flour, so it will give you a thicker, denser dough.
If you are making a cake, pancakes or other baked good where you hope to achieve a light consistency, avoid using bread flour altogether. The thickness of the dough will ruin the texture of your batter and the final product will not taste or feel right. Although the conversion is extremely simple, don't be misled--it will make a difference in the final product.
Look up how much all-purpose flour your recipe calls for.
Measure the exact same amount of bread flour.
Add this to your recipe.