Men are likely to live four years longer than they expected, while women could be underestimating their lifespan by a staggering seven years, according to new analysis.

Barnett Waddingham said its research suggests millions face a hidden financial shortfall in later life.

Underestimating longevity could leave men £20,000 and women £35,000 short on modest pension goals, the retirement specialist said. The figure is much higher than that for those with average pots of £50,000, who could face a £70,000 gap by retirement.

The company’s analysis showed that most people expect to live until around age 82 - but actuarial models based on pension scheme data show they’re likely to live significantly longer.

For men, the gap is around four years: while they expect to live to 82, the reality is closer to 86. Women also expect to reach 82, but many will live until 89 - underestimating their lifespan by seven years.

If someone plans to draw £5,000 a year from their private pension (on top of the state pension) and assumes a 17-year retirement from age 65 to 82, they would aim to have saved around £85,000.

But if they live to 86, as many men will, they’d need £105,000. For women likely to reach 89, the requirement jumps to £120,000. That’s a shortfall of £20,000 for men and £35,000 for women.

The situation becomes even more concerning when looking at women’s pension savings specifically. On average, women retire with significantly smaller pension pots than men.

Many manage to save only around £50,000 by the time they retire. But if they end up needing £120,000 to sustain them through retirement, they face a £70,000 gap - leaving them dangerously exposed and potentially far more reliant on state support later in life.

Men and women tend to assume they will live for roughly the same amount of time, but women typically outlive men by around three years. With longer lives and smaller savings, women face a uniquely challenging retirement landscape.

Jack Carmichael, associate and senior longevity actuary at BW, said: "The gap between expectations and reality on life expectancy is yet another seismic hurdle in the way of solving the gender pensions gap.

“Millions of savers are heading into retirement with unrealistic expectations and inadequate savings. Women in particular are facing a perfect storm: longer lives, smaller pension pots, and a far greater risk of running out of money.”

• Barnett Waddingham commissioned Censuswide to survey 5,032 UK employees and self-employed people aged 18+, at least 3,000 of which are over 50 and all of whom plan to retire in their lifetime. An additional 548 respondents who didn’t plan to retire were asked why not. This survey was conducted in summer 2024. The additional analysis was conducted in May 2025 using a bespoke life expectancy analysis methodology.