Pizza Stone vs Cast Iron

Thermally, cast iron is carbon steel

Gray cast iron publishes a thermal conductivity of 46 W/m.K against carbon steel's 50, a specific heat capacity of 490 J/kg.K against 470, and a density of 7.5 g/cm3 against 7.9. Multiply those out and the two land almost on top of each other.

So on crust, cast iron beats a stone by essentially the same margin a baking steel does. The 15-inch Lodge pizza pan is 9.91 published pounds and reaches 95 percent of oven temperature in about 23 minutes - the fastest of any surface on this site, because it is both dense and comparatively light.

The real argument, and it is not thermal

It is the rim. A pizza pan has a raised edge and two handles; a baking steel and a stone are flat plates you can slide a base onto from a peel. That difference changes the whole workflow.

With cast iron you either build the pizza on the cold pan and put it in the oven with the pizza already on it - which forfeits most of the preheat benefit and is the mistake almost everyone makes first - or you preheat the pan empty and then drop a dressed base into a 500 F dish with a rim in your way. The second works. It is fiddly, and it caps you at roughly a pizza an inch smaller than the pan.

The upside is equally real. It has handles, so getting it out is a normal kitchen action rather than a two-oven-glove event. It costs a fraction of what a steel of similar thermal capability costs. And most households already own a large cast iron skillet, which means the experiment is free.

What each is actually for

Cast iron pan: pan pizza, Detroit and Sicilian styles, deep dish, and anyone testing whether a surface upgrade would help before spending on a steel. The rim is a feature for those styles rather than an obstacle.

Stone: peel-launched round pizza, bread, and anyone who does not want to maintain seasoning or lift much.

Baking steel: peel-launched round pizza where the base is the specific complaint, and you want cast iron's physics with a stone's flat geometry.

The cheapest useful experiment in home pizza

Before you buy anything: preheat the biggest cast iron pan you own on the middle rack for 25 minutes at your oven's maximum, and bake a small pizza on it. If the base comes out transformed, your problem was the surface and a steel will fix it properly. If the base is about the same, your problem is somewhere else - most likely the oven temperature or the length of the preheat, both of which are covered in the preheat guide. That test costs nothing and it has saved more money than anything else on this site.