Converting muffin recipe to mini loaves?

I have some boxed muffin mix that I would like to make into mini loaves instead. The directions want me to cook it at 425 for 16-18 minutes for 12 muffins. How can I adjust this to make mini loaves (4.25x2.5x1.25) instead?

I would just lengthen the baking time 3-5 minutes. Check the doneness with the toothpick method. If not done after that time, go for 1 minute at a time until it tests done.

As it happens, I’m doing some baking with mix right now.

Someone with more baking experience than me can correct me if I’m wrong or overthinking it, but my mix box has directions for both muffins and loaves. A batch of 12 regular muffins is 400 degrees for 18-22 minutes, while mini loaves (5.5x3x2) are 350 for 45-50 minutes. Makes sense, since a loaf is thicker than individual muffins and would need longer to bake at a lower temperature so the outside doesn’t burn before the inside is baked.

My mix is not your mix, but you can probably extrapolate from the proportions. Figure maybe 375 for 30 minutes, since your loaf pan is smaller and the baking time appears to be shorter. If you want to hedge your bets, start with 20-25 minutes and check like Hockey Monkey suggests.

Thanks guys!