Working Hours Calculation from Excel Sheet

I have an Excel sheet which is exported from a Sharepoint list. This sheet contains odometer for heavy equipment which is updated manually and daily. for example equipment L has 20 records for last 20 days and each record contains the odometer. I need to an make extra column in the excel sheet for calculations to get the difference between last two odometer readings for each equipment. Not sure if this can be done in Excel or you need Coding and if I do C# is my preferable language to deal with