Although sea-ice concentration, extent and type can be measured with acceptable accuracy by satellite or airborne remote-sensing techniques, sea-ice thickness measurements are difficult to obtain accurately, even in situ. Modeling sea-ice volume and associated transport requires input data for ice motion as well as for the redistribution of sea-ice thickness and there is a need to develop new sea-ice models driven by the best available data. The majority of sea-ice thickness measurements in the Southern Ocean are derived from drill holes and, more recently, upward-looking sonar and electromagnetic methods. The most comprehensive sea-ice thickness dataset for Antarctic sea ice available to date is the one from the Antarctic Sea Ice Processes and Climate (ASPeCt) program, which includes 23 373 ship-based observations collected over two decades, but there are spatial and temporal gaps in the data. This work uses ice stage of development from four years (1995–1998) of National/Naval Ice Center (NIC) operational ice charts as a proxy for sea-ice thickness to produce model-input-ready Southern Ocean sea-ice thickness distributions on multiple temporal and regional scales. Evaluation of the basin-wide thickness distribution includes standard error propagation from ice-chart stage of development to gridcell thickness distribution, computation of thickness distribution anomalies and comparison with the ASPeCT dataset. The final product of the study is a diagnostic model of sea-ice volume transport in the Southern Ocean which uses the NIC-derived thickness distribution and sea-ice motion vectors calculated from 2 day composites of passive microwave radiometer images. The model provides large-scale sea-ice volume fluxes on a 10° longitude by 4° latitude grid and for established regions around Antarctica.