Image caption The cost of new equipment and cremating larger coffins have been blamed for the price rise. The average cost of a cremation at a public crematorium has risen by a third since 2010, the BBC can reveal.An adult cremation costs an average of £640, according to Freedom of Information responses from local authorities that run crematoriums in the UK.mage caption The cost of new equipment and cremating larger coffins have been blamed for the price rise. The average cost of a cremation at a public crematorium has risen by a third since 2010, the BBC can reveal.