Unfortunately manufacturers have yet to standardise loaf tin sizes which can make life a little tricky sussing out the capacity of your tin A good way to check is to measure how much water your tin will hold. A 900g (2lb) loaf tin will hold just over 1 litre (36fl oz) of water and a 450g (1lb) loaf tin will hold just over 500ml (18fl oz) so you will know if your tin is suitable for a certain recipe or not. Just remember that if your tin is very deep, or very shallow, then you will need to keep a good eye on the baking time and put all your ‘testing for doneness’ skills to good use!