Magento migration is a major undertaking. The complexity of the migration project grows sizably when the online store has lot of SKUs. The initial analysis can take anywhere from couple of hours to couple of weeks, depending on how thorough the analysis is set to be.
Our app is a great place to start. All you have to do is to copy the files, launch the app and wait for 15 minutes. You can get a quick report on how complex your current version of Magento is. So, download our free app and analyze your eStore.