More than seven million people in their 30s and 40s will lose out by £10,000 each under Government plans to increase the state pension age to 68.
Last week, the Work and Pensions Secretary David Gauke announced the UK state pension age increase from 67 to 68 would be brought forward,
Analysis by the House of Commons Library found the £74 billion the move will save works out to £9,800 per person on average across the 7.6 million people born between 1970 and 1978 who will be hit by the change.
The amount is approximately equivalent to around one year's worth of payments of the new state pension, which totals £8,300, the research said.
Under current plans, the state pension age for men and women will be equalised at 65 at the end of 2018, before rising to 66 in 2020 and 67 in 2028.
Debbie Abrahams, shadow work and pensions secretary, said: "This is a disgraceful and unjustified attack on the state pension by this Government, who are asking millions of people to work longer to pay for their failing austerity plans."
The Department for Work and Pensions (DWP) said it would save the equivalent of £400 a year per household.
A DWP spokesman said: "These changes will ensure that the state pension is both fair and sustainable for future generations.
"Under the simplified new state pension at its basic level, people in retirement will receive over £1,250 a year more than compared to April 2010."