Convert tonnes/acre to hectolitres/hectare
The conversion assumes that 80% of the grape is extracted to make up the wine. This is a big assumption so the conversion is only a rough working guide.
1 tonnes/acre = 2.5 tonnes/hectare (2.5 Acres in a Hectare)
Assume 80% of the grape is extracted to make the wine
2.5 tonnes/ha = 20 hectolitre/hectare
Therefore
1 tonnes/acre = 20 hectolitre/hectare