Cast iron is ferromagnetic, which means it works on induction cooktops without adapters, special bases, or any modification. The short answer to this question is an unqualified yes. But the more useful answer involves understanding why cast iron behaves differently on induction than it does on gas or electric coil, and what you need to change about your technique to get good results.
The compatibility itself is simple. Induction cooktops generate an alternating magnetic field from a copper coil beneath the glass surface. That field induces eddy currents in any ferromagnetic metal placed above it, and those currents generate heat directly inside the pan. Cast iron is almost entirely iron. It grabs a magnet firmly and triggers the induction sensor instantly. If you already own cast iron and you are switching to induction, your skillets will work on day one.
The problem is what happens after you turn on the burner.
The Hot Spot That Nobody Talks About
Hot spots on induction are more severe with cast iron than with any other compatible material. The reason comes down to physics that no amount of seasoning or technique can override.
The induction coil inside your cooktop is not the same diameter as your pan. A burner marketed as suitable for 10-inch cookware might have an actual coil diameter of 5 to 6 inches. Thermal imaging tests on portable induction units like the Duxtop 9600LS have measured the actual heated zone at barely 5 inches across, even though the surface markings suggest 8 inches. That coil heats only the metal directly above it. Everything outside that circle depends entirely on lateral heat conduction through the pan walls.
Here is where cast iron fails the math. Its thermal conductivity is approximately 50 watts per meter-kelvin, roughly one-third that of the aluminum alloys used in cookware (around 160 W/mK). Heat moves sideways through cast iron slowly. Independent infrared thermometer tests on cast iron skillets consistently show temperature differences exceeding 150 degrees Fahrenheit between center and edges, even when the burner size matches the pan. Aluminum discs under the same conditions show less than 30 degrees of variation. On induction, where the coil is often smaller than the pan base, the concentration effect is worse.
The practical result is a ring pattern. Your food sears aggressively in a circle matching the coil diameter while the outer two inches of the cooking surface barely reach medium heat. If you have ever noticed eggs cooking unevenly or a steak with a dark center stripe and pale edges on induction, this is why.
Why Pre-Heating Matters More on Induction
On gas, the flame licks up the sides of the pan and provides some radiant heating to the outer edges. On a radiant electric coil, the element typically spans most of the pan's base. Induction provides zero incidental heating outside the coil footprint. The only way heat reaches the outer rim of a cast iron pan on induction is through conduction from the center outward.
This means you need patience. Pre-heat on low or medium power for 3 to 4 minutes before cooking. The temptation on induction is to crank it to maximum because the response is instant, but doing that with cast iron creates an extreme center temperature before the edges have time to warm up. Flour tests on similar portable units confirm the same 5-inch hot zone pattern, and thermal camera footage shows center temperatures exceeding 500 degrees Fahrenheit while the rim sits below 350 within 3 minutes on high power. That gap creates thermal stress that, according to reports on cooking forums, can crack thinner or older cast iron over repeated cycles.
The slow pre-heat lets the metal equalize. After 3 to 4 minutes on medium, the temperature differential across a 10-inch skillet typically drops to 40 to 60 degrees, which is workable for most cooking tasks.
Matching Pan Size to Your Coil
The contact diameter of your cast iron matters more on induction than on any other stove type. A 12-inch skillet has a flat contact area of roughly 8 to 8.5 inches, but the marketed "large burner" on many induction cooktops contains a coil of only 7 to 8 inches. That leaves up to an inch of pan base with no direct energy input on each side.
For a 10-inch skillet like the Lodge, the mismatch is less severe. The flat contact area of a standard 10-inch cast iron pan is approximately 6.5 inches, which aligns with common residential induction coils reasonably well. This is why most people on r/castiron and in Amazon reviews who report great results with cast iron on induction happen to use 10-inch skillets. The 12-inch owners are the ones posting about uneven cooking.
If your induction cooktop has a power boost or "bridge" mode that activates multiple coils, that changes the equation. Dual-zone bridge elements effectively double the heated area and make larger cast iron practical. But most single-zone residential burners top out at 7 to 8 inches of actual coil coverage regardless of the printed ring size on the glass.
Protecting the Glass Surface
The cooking surface on induction cooktops is tempered glass, and it scratches permanently. Rough cast iron bases are the primary offender. The same pebbly texture from sand-mold casting that characterizes most budget cast iron (Lodge, Victoria, Camp Chef) creates friction points that score the glass every time the pan moves.
The rule is straightforward. Lift, never slide. Every single time you reposition the pan, pick it up completely. This feels unnatural if you are coming from a gas stove where shoving a skillet forward to the cool zone is reflex.
If your cast iron base is particularly rough, sanding with 80-grit followed by 120-grit paper and a fresh oven seasoning cycle creates a smoother contact surface. This is the same approach that works for glass top stoves in general. Machined-smooth cast iron (Stargazer, vintage Griswold) eliminates the concern entirely, though at a premium price.
Enameled cast iron has a glass-smooth base by design and poses minimal scratch risk. If you are buying new cast iron specifically for an induction kitchen, enameled options from Lodge or Le Creuset are gentler on the surface. For the material differences, the comparison between enameled and bare cast iron covers the tradeoffs.
When Cast Iron Excels on Induction
Despite the hot spot limitation, cast iron remains one of the best materials for induction cooking in specific scenarios. The same thermal mass that causes slow warm-up becomes an advantage once the pan is fully heated. When you drop a cold steak onto a pre-heated cast iron skillet on induction, the surface temperature barely dips. The stored energy in 5 pounds of iron overwhelms the cooling effect of the food in a way that thin stainless steel or aluminum cannot match.
For searing, deep frying, and any task where temperature stability matters more than speed, cast iron on induction is genuinely excellent. The key is allowing the full pre-heat time and accepting that the effective cooking zone is the center circle matching your coil diameter.
Dutch ovens on induction work particularly well for braising and stewing. The liquid inside distributes heat naturally through convection, making the coil-size mismatch irrelevant once the contents are at temperature. Owner discussions on r/Cooking confirm the same pattern, with multiple users reporting that enameled cast iron Dutch ovens perform reliably on induction because the liquid distributes heat naturally through convection.
What I Would Do Differently
From the research I have gathered across thermal imaging tests, long-term owner reviews, and manufacturer documentation, the pattern is consistent. The people who struggle with cast iron on induction are almost always doing one of three things: using oversized pans on undersized coils, pre-heating on maximum power, or sliding the pan across the glass.
If you already own cast iron and are moving to induction, you do not need new cookware. You need a 3-minute pre-heating habit on medium power and the discipline to check your existing pans with a magnet test before assuming anything about compatibility. Every cast iron pan you own will pass that test. The question is whether your specific pan size and your specific coil size create a workable match, and now you know how to evaluate that.
For someone buying their first cast iron pan specifically for induction, a 10-inch skillet is the practical sweet spot. The Lodge 10.25-Inch Cast Iron Skillet matches standard residential coil sizes and costs under $30 at time of writing. Its base is rough from the sand-mold casting process, so you will want to sand it smooth with 80-grit and 120-grit paper before using it on glass, or simply commit to the lift-never-slide habit.
