Tipping for free tours- advice please!

I tip what the typical cost of a tour is when paying for a tour.

Greetings from Ireland,

Don't worry about it because once you do your 'free' tour, the guide will be very clear at several times throughout the tour about what is the expected tip.
They aim for €5 minimum per person and hope for €10 average per person.
However, in fairness to the 'free' tours, you are free to give them €1 if you like, or nothing (like some people sadly do).

Do tip something of course, these guides usually have to pay a per-person marketing fee to their masters at HQ, hence the "group photo" (this is how the office counts how many are on the tour)

Some of the guides on these tours are very high quality, some of them are mediocre in terms of the accuracy of the info they'll give you. I've experienced both.

Enjoy!

Slainte! good health
Stephen McPhilemy
Rick Steves Ireland Tour-Guide
Dingle, Derry & Dublin

Thanks for the advice!