: There was a thread about this point a while back.
: My two main points were: first, that there seem to have been a lot of hobbits in the Shire so you would have expected that the human population of Eriador (including the Dunedain)would have recovered to a comparable extent; and second, that the Rangers represented a "Standing army" , albeit a small one. Both these facts would tend towards the population of the Dunedain being rather larger than the thirty men of Halbarad's troop would at first suggest.

: A standing army (a body of men kept under arms at all times)is quite a sophisticated phenomenon, for example England didn't have one until about 1650, the existence of the Rangers would need a reasonable infrastructure to back it up. That infrastructure would have to include farmers and craftsmen to provide their food supplies, weapons/armour, clothing and horses.

: All this points to the existence of a Dunedain civilian population, possibly living in homesteads and hamlets without the need of anything larger than the occasional small fortified village. Where could this population have lived? - personally I would place it in the area surrounding Lake Evendim and particularly in the Evendim Hills. I say this for a number of reasons: Annuminas (a ruin on the lake-shore) was one of the earliest settlements of the followers of Elendil, the area is close to both the elves of Lindon and the dwarves of the Blue Mountains - useful for trade, and as the threats to the Shire and Breeland generally came from the East and Northeast any defensive effort by the Rangers to protect these areas would automatically defend the Evendim area as well.

: As for population size, this would be even more speculative. However, if the thirty-man troop of Halbarad represents a normal Ranger unit size some extrapolation becomes possible. The minimum working number would be two such troops - one on active service the other in reserve/resting. This would still be precarious, given the likelyhood of casualties so I would expect the Rangers to consist of minimally three such troops - say around a hundred men all told. To support this number of non-productive people (ie not producing food or other necessities) I would guess that the adult male Dunedain population would have to have been at least ten times greater. Add on the women and children and old men then you come to a minimum total Dunedain population of around 3,000.
: In times of acute danger the Dunedain from these figures would be able to field a force of at most 500-600 men - this number tallies fairly well to the numbers given by Tolkien to the reinforcements sent to Minas Tirith by the fiefs of Gondor. I would suggest that the Dunedain population was probably similar to that of a lesser Gondor fief such as Morthond Vale or Pinnath Gelin.

>> I believe in 60- 150 rangers in all, as mentioned, only a few could be brought up in a hurry, and there were other duties to attend as well as the Ring War. However, I also belive that you should at least double the number of soldiers available to the fiefs of Gondor. no matter if they knew that the main battle would be fougth at Minas Tirith, they would leave at least the equivalent of the "expeditionary force" to defend their own homes against Corsairs- remember that their wifes and children were there. In today's military practice it is VERY common to divide your force by thirds, and Tolkien gives the Gondorian army the same practice (U.T.), thus I would suspect that we have to triple the numbers of men sent to the Pellenor to gain the total force of Gondor's fiefs' armies, or possibly more: