Languages can make use of phonetic duration to signal two kinds of meanings. The first is a lexical, phonological contrast. For example, in Japanese [kata] with a short [t] means ‘frame’ and [katta] with a long [tt] means ‘bought’. This sort of contrast is usually limited to a binary distinction, and its phonetic properties have been well studied for many diverse languages. The other use of phonetic duration is to express pragmatic emphasis. Speakers of some languages can use lengthening to express emphasis, as in the English example Thank you sooooooo much. This lengthening can employ multiple degrees of duration, beyond the more standard binary contrast. This second use of duration has been understudied, and this paper attempts to fill that gap. To that end, this paper reports the first experimental documentation of the consonant lengthening pattern in Japanese, which expresses pragmatic emphasis. The results show that at least some speakers show six levels of durational distinctions, while other speakers show less clear-cut distinctions among different levels of emphatically lengthened consonants. Nevertheless, all but one speaker showed a linear correlation between duration and level of emphasis.