Linguists are able to describe, transcribe, and classify the differences and similarities between accents formally and precisely, but there has until very recently been no reliable and objective way of measuring degrees of difference. It is one thing to say how varieties are similar, but quite another to assess how similar they are. On the other hand, there has recently been a strong focus in historical linguistics on the development of quantitative methods for comparing and classifying languages; but these have tended to be applied to problems of language family membership, at rather high levels in the family tree, not down at the level of individual accents. In this article, we outline our attempts to address the question of relative similarity of accents using quantitative methods. We illustrate our method for measuring phonetic similarity in a sample of cognate words for a number of (mainly British) varieties of English, and show how these results can be displayed using newer and more innovative network diagrams, rather than trees. We consider some applications of these methods in tracking ongoing changes in English and beyond, and discuss future prospects.