A spokesman for the zoo said this calculation is based on a reduced cost base, with reduced hours and limited spend across all departments.
"Should there be further necessary restrictions or lockdowns put in place over the coming months and into autumn 2021, we may have to reconsider financial support options," the spokesman said.
"Based on an average cost per month", Dublin Zoo has enough reserves to last into autumn 2021, he added.
The popular visitor attraction received a major boost this week after the Government announced the reopening of outdoor attractions on April 26 - meaning staff can prepare to welcome back the public.
The zoo has been closed for three-quarters of the last year due to Covid-19, bringing ticket sales income to zero.
"We are very fortunate to have an incredible team," the spokesman said.
"Our keeper staff are some of the best in the world and the routines they have created for the animals keep them well stimulated, even while the gates have been closed to the public.
"While the animal's routines have not changed much in the last few months, thanks to the hard work of the team, they have certainly noticed that there have been less people around and the return of the public will provide positive stimulation."
Meanwhile, the zoo is "in the early stages of planning our design concepts and are cautiously optimistic about being able to hold the extremely popular Wild Lights exhibition this year". However, a decision has yet to be made on whether it will run its summer camps.
"We have yet to make a decision on summer camps, and any decision will be informed by the ongoing restrictions," the zoo spokesman said.
Last November, the zoo set up a 'Save Dublin Zoo' fundraising campaign to help cover the cost of animal care.
Dublin Zoo said it costs €500,000 a month to feed, house and provide care for the animals.
In December, Junior Minister Patrick O'Donovan announced €2m in State funding for the zoo.
Tickets for Dublin Zoo will be going on sale on its website in the coming weeks, and will not be sold at the gate. Visit dublinzoo.ie for more information.