My 27 inch fixie broke and all I can afford is to convert my 26 inch old moutain bike into a fixed gear. Do people do this often and is it as comfortable as a 27 inch fixie? Either way I'm going to convert it I'm just trying to get feed back on what it may be like.

A fixed gear bike means that there is no dérailleur so you are just constantly pedaling (unless the fixed gear is equipped with the ability to coast). A mountain bike has fatter ties, which will make fixed gearing even harder to pedal.

Once momentum of the pedals get going the pressure it takes to pedal should be the same that's why a fixed gear is so easy to ride. And if it could coast it would be a fixed gear it would be a single speed. And I know plenty if people that have converted mountain bikes.

*wouldn't be a fixed gear