We show how the wide range in strengths of intensifying degree adverbs (e.g. very and extremely) could be explained by pragmatic inference based on differing cost, rather than differing semantics. This predicts a linear relationship between the meaning of intensifiers and their length and log-frequency. We test this prediction in two studies, using two different dependent measures, finding that higher cost does predict stronger meanings. We discuss the implications for adverbial meaning and the more general question of how extensive non-arbitrary form-meaning association may be in language.