Baking Time Adjustment Calculator

When you use a different tin size with the same amount of batter, the depth changes. A larger tin gives shallower batter that bakes faster. A smaller tin gives deeper batter that needs longer, often at a slightly lower temperature, to cook through without burning the outside.

For significantly deeper batters (a much smaller tin), reduce the temperature by 10-15°C to give the centre time to cook without over-browning the crust. For a larger, shallower tin, keep the same temperature and simply start checking earlier — increasing the heat is not recommended as it risks burning the top before the inside is set.

This gives an indicative estimate only — the exact timing depends on your oven, the recipe and the tin material. Always check your cake 5-10 minutes before the calculated time. Insert a skewer into the centre — if it comes out clean, the cake is done. Ovens vary significantly, so visual and skewer checks are essential.

Yes, the principle applies to sponges, fruit cakes, and brownies. However, very dense cakes like fruit cakes are more sensitive to depth changes and may need proportionally more extra time when made deeper.

For small changes in tin size (within 5cm), adjusting the time alone is usually enough. Moving to a much smaller, deeper tin gives a deeper batter, so reduce the temperature by 10-15 degrees C and allow a little more time to stop the outside overcooking before the centre is done. Moving to a larger, shallower tin bakes faster, so keep the same temperature and reduce the time, checking early with a skewer.