The current ex situ analytical methods to determine concentrations of dissolved organic carbon (DOC) are largely inadequate to form a dynamic understanding of the global carbon cycling, especially given the urgent need to understand how the oceans are responding to increasing concentrations of atmospheric CO2 and climate change. Here we establish a DOC algorithm, referred to as DOCUVFW, that is based on absorption characteristics of dissolved organic matter in the wavelength range of 275-443 nm. The algorithm performs uniformly for coastal and pelagic waters, as well as inland waters with DOC concentrations varying by several orders of magnitude. By applying the DOCUVFW algorithm, the three-dimensional distribution of oceanic DOC could be quantified via ocean color observed complementarily using field-observation spectral data and satellite remote-sensing images.