Technical divers abide by the rule of thirds to help them remain safe. Divers may want to top off their previously used cylinders with air from the boats compressor or even ‘transfill’ from another cylinder to take advantage of the remaining gas in their cylinders. The Top Off Mix tool will tell you what mix to expect based on a given starting pressure and starting mix after topping with air or some other mix.
Tap on the bookmark icon to recall a previously saved calculation or to save this calculation for future use.
You can easily make the calculations using Metric or Imperial/US by selecting the “Settings” tab (if it is not visible on the current screen select “More”) and changing the system to the one desired.