How much is 10 mins in the sun equal to on a sunbed? =D
About 30 seconds. Think about it. You are only supposed to stay a maximum of 15 minutes in a tanning bed. Doing that you get a tan. If it was equal to the amount of time you spend in the sun then you wouldn't need a tanning bed. 18 minutes outside and most people don't see any kind of change.
Probably the same, I believe the tanning beds are made to mimic the sun as closely as possible.