A liquid application apparatus includes a first container, an applicator, a squeezer, a second container, a retreat passage, a filter, an on-off valve, and a sensor. The first container stores a pretreatment liquid before image forming. The retreat passage communicates the first container with the second container. The filter is disposed on the retreat passage to remove foreign substances from the liquid. The on-off valve is disposed between the second container and the filter on the retreat passage. The sensor is disposed at the first container to detect a liquid level of the first container in at least two positions different in height and obtain a flow rate of the liquid in the retreat passage based on a period during which the liquid level moves between the positions when the on-off valve is opened and the liquid stored in the first container is transferred to the second container.