Cast Iron Seasoning Oil Calculator

How it works

Interior area = π·r² + π·d·wall height · Total area = interior × 2 if outside too · Oil per coat ≈ area × 0.03 ml/in² (then wiped back) · Total = per coat × coats

The single most important rule of seasoning cast iron is that the oil layer must be almost invisibly thin. You pour on a small amount, spread it over the whole surface, then wipe nearly all of it off with a clean cloth until the pan looks dry, not greasy. A thick coat does not bake into a harder finish — it turns sticky and gummy. So this calculator sizes the amount you pour on, knowing most of it comes back off on the cloth. Larger pans and seasoning the outside as well as the inside need proportionally more, and each additional baked coat builds up the slick, durable patina. Bake each coat past the oil’s smoke point so it polymerises into a solid, non-stick layer.

Worked example

A 10-inch skillet with 2-inch walls has an interior area of about π·5² + π·10·2 ≈ 78.5 + 62.8 = 141 in². Seasoning inside and out doubles that to ≈ 283 in². At 0.03 ml per in², you pour on about 8.5 ml (1.7 tsp) per coat, then wipe it back — roughly 25 ml over three coats.

Frequently asked questions