Researchers including those from University of Bufallo in the US, found that the percentages ranged from less than 0.1 per cent in Ethiopia to 96.4 per cent in Serbia.
The team identified the proportion of households in which soap and water was present at a hand washing place in the home.
Researchers found the availability of soap anywhere in the dwelling ranged from nearly 21 per cent in Senegal to 99.1 percent in Iraq and Serbia, according to the surveys that included data on soap availability in the home.
They also found that compared to Africa, the availability of soap and water was higher in the Eastern Mediterranean region, and ranged from 42.6 per cent in Afghanistan to 91.5 per cent in Iraq.
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In Southeast Asia, nearly 79 per cent of households in Bhutan had soap and water, compared to 21.4 per cent in Bangladesh, researchers said.
The poorest households often had extremely low access to soap and water for hand washing, compared to wealthier households (for example, six per cent and 85 per cent in regions of Nepal).
The findings underscore the need to improve access to soap, along with hand washing behaviour in general, in many impoverished countries, said Swapna Kumar from University of Buffalo.
The study was published in the American Journal of Tropical Medicine and Hygiene.