Death rate of captured slaves during the Middle Passage 1501-1866 by destination

Throughout the Atlantic slave trade, 14.5 percent of captured slaves who embarked on ships in African ports died en route to their destination. Voyages from Africa to the Spanish Americas had the highest mortality rates, where almost one fifth of all captives died during the journey. Voyages between Africa and Brazil had the lowest mortality rates, where approximately one in eight did not survive. There is a clear correlation between voyage lengths and Middle Passage death rates; journeys between Africa and Brazil took an average of 45 days, whereas journeys to the Spanish Mainland Americas took 78 days on average. In addition to voyage lengths, factors such as overcrowding (which increased the rate of disease transmission), violence, insurrection, and high suicide rates also contributed to the high mortality rates along the Middle Passage.