How kWhrs are calculated
Meter readings for electricity meters are already stated in kWhrs so no conversion is required. In the meter readings list the usage since last reading and the kWhrs since last reading will be the same.
For gas meter readings a conversion automatically occurs to convert the readings from units of gas to kWhrs. This conversion is different depending on whether imperial or metric units are being measured (you set this up in the custom data tab for the meter or probe itself - enter a new custom data item for 'Data type' and enter a text value of either Gas units imperial or Gas units metric). The kWhrs column for gas readings will therefore not display the same numbers as the usage since last column which simply shows the gas units used.