Combine INT, TIME fields and compute Elapsed Percentage

Need calculation and conversion help... Columns: [Days] INT [hh:mm:ss] Time [AllowedRuntimeMinutes] INT Need to combine [Days]+[hh:mm:ss] as the duration the query has been running, and then calculate the elapsed percentage over the allowed run time. So possibly some form of ([Days]+[hh:mm:ss] as Duration)-AllowedRuntimeMinutes/AllowedRunTimeMinutes*100 ?