Conversion guides

Chocolate sponge cake on a white plate with two slices cut out

Sugar form	°C	°F
Thread	107	225
Soft ball	119	238
Firm ball	125	256
Hard ball	138	280
Soft crack	151	304
Hard crack	168	336

Cake tin sizes

As a rule of thumb, a square tin holds about 25% more than a round tin of the same size. If you're using a square tin for a round tin recipe, keep the temperature the same, and turn the cake during baking, as the corners tend to cook faster than the middle.