A sack of maize bought in one part of Ghana may not contain the same amount as a sack bought elsewhere, according to new findings from the Ghana Statistical Service (GSS).
The finding is part of Ghana’s first Non-Standard Units Survey (NSUS) 2026, which has revealed major differences in how agricultural produce is measured and traded across the country.
For years, farmers, traders and households have relied on common local measures such as sacks, buckets, tins, cups, heaps and bundles. While these units are familiar, the survey found that they often represent different quantities depending on the region, commodity and how they are filled.
The GSS said the differences have made it difficult to produce accurate and comparable agricultural statistics.
“The same unit often represents different quantities across commodities and regions, making consistent agricultural statistics a challenge,” the Service said.
One of the biggest differences was found in maize trading. The survey showed that a cocoa (jute) sack of dried yellow maize weighed an average of 131.1 kilograms in the Greater Accra Region, compared with 198 kilograms in Bono East Region.
That means two farmers selling what is described as the same sack of maize could actually be trading quantities that differ by nearly 67 kilograms.
The finding raises questions about the accuracy of agricultural estimates that depend on counting sacks rather than measuring the actual weight of produce.
The challenge is not limited to sacks. The survey found differences in other common measures used by farmers and traders, including buckets, tins and size descriptions such as small, medium and large.
At the farmgate level, a white paint bucket of dried maize also showed wide differences. A small bucket weighed an average of 3.705 kilograms, while a large bucket weighed 14.607 kilograms, showing how much quantities can change even within the same type of container.
Similar variations were found in other crops. A blue rubber bucket of local tomatoes weighed an average of 3.827 kilograms nationally, but ranged from 3.496 kilograms in the Volta Region to 4.122 kilograms in the North East Region.
The GSS said these differences matter because agricultural data is used to guide important decisions, including food planning, farmer support programmes and national economic estimates.
The NSUS provides conversion factors that allow traditional measures to be translated into standard units such as kilograms and litres.
“The NSUS provides a stronger foundation for measuring production, trade, consumption and food security,” the GSS said.
The survey covered markets, households and farmgates across Ghana, weighing commonly used local measures to develop national conversion factors.
The findings also showed that some measurements are more reliable than others. Containers with fixed sizes, such as bottles used for liquids, recorded more consistency, while loose measures such as heaps, bundles and size-based descriptions varied widely.
The GSS said the new conversion system will support improvements in agricultural statistics, household consumption surveys and inflation measurement.
The Service is also developing a digital database containing the conversion factors and images of local measurement units to support future surveys.
The NSUS represents a major step in improving how Ghana measures its food economy, ensuring that traditional trading practices used daily by millions of people can be accurately reflected in national data.
