People aged between 35 and 44 years old think they need an additional £612 a month in order to feel financially secure.
Aviva's Times of our Lives Report asked Britons what their desired extra monthly income is and this age group came out on top.
People aged 65 and over believe they only need an additional £23 in order to be comfortable, while the average figure was £466.
Simon Warsop, Business Development Director at Aviva, said: "In the past six months Britain's 'squeezed middle ages' have become ever more pressured. Responsibilities are mounting as they are more likely to have the additional costs of running their own home."
Despite their growing financial concerns, 38 per cent of individuals do not think they could do without their car, while 29 per cent are unwilling to forego their summer holiday.
In terms of key goals, people want to buy their first house at the age of 25, get married at 27 and pay off their mortgage by the age of 50.