A tool to measure the depth of one or more through-silicon vias, the tool fabricated in silicon to include a microfluidic chamber that is positioned over the one or more through-silicon vias, further including a fluid actuation chamber to inject fluid into the microfluidic chamber and into the one or more through-silicon vias, and a pressure sensing chamber to sense the fluid pressure to indicate when the one or more through-silicon vias are filled with the fluid.