Attempts to measure phonological acquisition have largely focused on segments, with less effort made to examine whole-word productions. This article proposes four measures designed to estimate a child's whole-word abilities: 1. the PHONOLOGICAL MEAN LENGTH OF UTTERANCE, a measure of whole-word complexity for both child and target words, 2. the PROPORTION OF WHOLE-WORD PROXIMITY, a measure of the proximity between the child's word and its target form, 3. the PROPORTION OF WHOLE-WORD CORRECTNESS, a measure of the number of words produced correctly relative to the sample size, and 4. the PROPORTION OF WHOLE-WORD VARIABILITY, a measure of how often a child produces words in distinct phonological shapes. The central measure is the Phonological Mean Length of Utterance, which can be used to identify a child's stage of acquisition, to assess proximity to target words, and to evaluate the complexity of words. The value of the new measures will be demonstrated through preliminary applications to a range of contexts; i.e. monolingual children acquiring English (five children, 0;11 to 1;5), Cantonese (one child, 1;7), and Spanish (5 children, 2;2 to 2;11), bilingual children acquiring Hungarian-English (one child, 2;0) and Spanish-English (3 children, 2;4 to 2;11), children with phonological impairment (eighteen children, 2;11 to 5;3), and children with cochlear implants (six children, 4;5 to 7;11).