The U.K. assessment shows that the initial cost of sending an individual to a third country will be around £169,000 - including a £105,000 payment to the third country, along with flight tickets and administration costs.
But it also predicted an estimated saving in costs over four years of £106,000 for each asylum seeker removed to Rwanda, or another third country.
This could rise to £165,000 if accommodation costs grow at the trend rate that has been observed since 2019, it added.
The assessment warned that the figures were "highly uncertain," and said the plan would need to deter around 37 percent of small boat crossings for the costs to be recouped.
The U.K.'s Conservative government has made tackling immigration a priority, and it was a key promise as the country left the European Union.
It wants to outlaw asylum claims by all irregular arrivals and transfer them to "safe" third countries, such as Rwanda, to stop thousands of migrants from crossing the Channel on small boats.
The government said up to £165,000 could be recouped due to saved costs from reduced asylum support.
London also hopes the program will act as a deterrent.
The government has highlighted the cost of housing asylum seekers while their claims are being processed, as it attempts to win support for the bill in parliament.
More than 45,000 migrants arrived on the shores of southeast England on small boats in 2022 - a 60-percent annual increase on a perilous route that has been used by more people every year since 2018.
Beyond the cost, the proposed law, which is currently being debated in parliament, has come under fire over the potential treatment of asylum seekers in Rwanda.
"If enacted in its current form, the bill would leave tens of thousands of refugees unable to access the protection they are entitled to under international law," said Enver Solomon, head of the Refugee Council.
"It would cause hardship, cost billions of pounds, and do nothing to alleviate the current crisis and pressures within the asylum system."
The Rwanda plan, announced by then-prime minister Boris Johnson last year, was blocked at the last minute by the European Court of Human Rights, which is separate to the E.U.
The government scheme is still mired in legal challenges. To date, no deportation flights to Rwanda have taken place.
Judges in London will hand down their judgment on the legality of the scheme on Thursday.