Apologies miless2111s I'm a bit lost, can I be more specific so that I can try and understand better.

Column (Number20) - contains my planned meterage
Column (Number19) - contains my meters complete
Column (Text 30) - is where I want to see the meterage progress so I use the below formula in column Text 30 -

Format([Number19]/[Number20]*100 & "% ","0%")

This calculates the correct percentage and format when column 19 has progress, however when is is zero I get #ERROR. And there are columns I want to manually enter hence why I needed a new column. I created (text 21) to be that column.

Any help would be appreciated