How do you calculate whether injured employees are returning to work within an appropriate time frame or if they are out on comp for weeks at a time? The Return to Work Ratio (RTW) measures the effectiveness of your transitional duty program. The ratio calculates how long it takes employees suffering a lost time injury to return to work in either a transitional duty assignment or full duty. The RTW Ratio calculates total lost days and total claims to show the percentage of employees that have returned to work within the first few days after the injury. The RTW Ratio helps you categorize lost work days to ensure that employees aren’t off work too long.