This application provides the ton miles calculations for round-trip operations in the oil field services. This app was developed based on API Recommended Practice 9B (API RP 9B). This version uses the drill string with drill pipe, heavy-weight and two drill collars. You can contribute with suggestions for improvement, reporting bugs and sharing with your friends. Thanks DISCLAIMER: These tools & materials are provided 'as is' without warranties of any kind, express or implied. Please verify the tools provided by this application by yourself before you use them. Ensure you understand the impact of using these tools. Any use you choose to make of these tools & materials is undertaken by you entirely at you own risk.