How do speakers coordinate planning and articulation of more than one word at the same time? Here, we test whether they dynamically estimate how long it takes to (i) plan and (ii) articulate the words they intend to produce as a means of achieving such coordination. German speakers named two pictures without pausing, while their eye-movements were recorded. In line with previous reports, after their gaze left the first picture, speakers took longer to start speaking (i.e., the gaze-speech lag was longer) when the name of the first picture was shorter. But while gaze-speech lags were also longer when the second picture was harder to name, the two effects did not interact. We argue that speakers’ flexible planning abilities might be accounted for by reactive, rather than proactive planning mechanisms.