Shropshire Council says that revenue figures provided to the public as part of the consultation were incorrect and has now issued an up-to-date version.
There has been no change to the which option produces the most money, with a new pool on land at Shrewsbury Sports Village still shown as the most profitable.
However, the running costs for a new pool built on the Quarry site are considerably reduced.
The figures also show that the current and projected annual subsidy for the Quarry Fitness and Leisure Centre, whether it is refurbished or renovated, is £195,811 - instead of £89,374 as originally reported.
Shropshire Council says that a new pool at Shrewsbury Sports Village would now generate a profit of £250,295 a year, as opposed to a £194,994 profit indicated previously.
The option of building a new pool at the Quarry site now shows as requiring a subsidy of £29,996, a year instead of £79,996, while options at Clayton Way and Ellesmere Road are listed as costing £27,539 a year, instead of £77,539.
Revenue figures are not listed for the option at Shrewsbury College, although they are described as being "between a full new build and the sports village option".
So far around 1,200 people have responded to the council's consultation.
The month extension means no decision is expected on the preferred option before February 2016.
Councillor Steve Charmley, Shropshire Council's Cabinet member with responsibility for leisure services, said people needed to have the chance to view the new data.
He said they would also be able to comment on the new information even if the have previously responded.
He said: "Due to these changes we felt that it was only fair to extend the consultation.
"I would like to thank all of those people that have commented so far. We are listening and these comments have, in part, led to these changes. Please take a moment to read this updated information and let us know your thoughts."
Councillor Charmley insisted that the council has no preferred option and would work to provide the one favoured by the public, within "financial parameters".
The consultation will now close on Friday, October 30, and people can complete a supplementary survey by visiting http://new.shropshire.gov.uk/get-involved/swimming-provision-in-shrewsbury/
The council has also said that all those who have already replied, and supplied their e-mail address, will be contacted about the changes.