Both are the skin thickening in response to pressure. The difference is how that pressure arrives, and it changes what you do about them.
A callus spreads
A callus is broad and diffuse, forming where pressure is spread over a wide area — the heel, the ball of the foot. It has no defined edge and usually does not hurt much. It is the foot armouring itself.
A corn concentrates
A corn forms where pressure is concentrated on a small point, and it develops a hard central core that presses inward. That core is why corns hurt in a way calluses do not — it acts like a stone pressing into the tissue beneath with every step.
Hard corns sit on the tops and sides of toes, over the joints, where a shoe rubs. Soft corns sit between the toes, usually the fourth and fifth, kept white and rubbery by trapped moisture.
Treating them
Both start the same way: soak to soften, then file gently with a pumice stone. Vinegar and water, one part to two, is particularly effective at breaking down the keratin. Never cut either one.
The difference is what comes next. A callus needs the pressure spread out — a cushioned insole, wider shoes, a metatarsal pad. A corn needs the pressure taken off the point entirely, which means a doughnut-shaped pad around it rather than a flat pad over it.
For a soft corn between the toes, the treatment is dryness. Separate the toes with a small piece of lamb's wool or a gel spacer, and dry carefully after washing. A soft corn kept dry usually resolves on its own.
Skip the medicated pads
Corn plasters containing salicylic acid do not distinguish between the corn and the healthy skin around it. On a normal foot they often leave a raw ring. On a diabetic or poorly circulated foot they can cause an ulcer. There is no version of these worth the risk.
Find the cause
- A corn on the top of a toe — the toe box is too shallow.
- A corn on the side of the little toe — the shoe is too narrow.
- A corn between the toes — the toes are being squeezed together.
- A callus under the ball — weight is landing too hard there; check for a worn sole or a heel that is too high.
Corns over a toe knuckle frequently accompany a hammer toe or mallet toe, where the joint is bent and rides against the shoe. Treating the skin without addressing the toe position means it returns indefinitely.
Chamomile oil calms the irritated skin around a corn — see corns and calluses.
Padding that actually works
The most common mistake is putting a pad directly over a corn. That adds bulk on the exact spot already being pressed, and inside a shoe it makes things worse.
The pad goes around the corn, not on it. A doughnut of felt with a hole at the centre transfers the load to the ring of healthy skin, so the corn sits in a void and stops being compressed. Cut your own from adhesive felt if you cannot find the shape.
For a soft corn between the toes, the goal is separation and dryness rather than cushioning. A small piece of lamb's wool — not cotton wool, which compacts and holds moisture — keeps the surfaces apart and lets the skin dry.
Replace padding daily. Left for days it becomes damp and compressed, and a macerated pad against skin causes its own problems.