Abstract: An adjustable spacer tool for spacing balusters includes an extendable pantograpic assembly having a first and second end and including evenly-spaced parallel uprights and X-shaped sets of cross-bars pivotally connected to one another. Each X-shaped set is pivotally connected to a pair of uprights adjacent upper ends thereof and pivotally and slidably connected to the uprights adjacent lower ends thereof. An arm, finger and cam extend outwardly from each end of the assembly to provide spacing between each end of the assembly and a desired surface for various sets of same-width balusters. Each arm is pivotally connected to one end of the assembly and to one end of the finger. The other end of the finger is pivotally and slidably connected to a respective end of the assembly. Each cam is pivotally connected to the arm distal the assembly. Removable connections permit adjustment of the overall length of the tool and replacement of parts.