The average Briton rates their "life satisfaction" as 7.4 out of 10, according to the first annual results of David Cameron's so-called happiness index.
Asked how worthwhile they found their activities, the average response was even higher - at 7.7 out of 10 - research by the Office for National Statistics (ONS) found. But one in five rated their anxiety levels at more than five out of 10.
Women tended to have a greater sense than men of life satisfaction and that what they do is worthwhile, but also reported higher levels of anxiety.
People aged 16 to 19 and 65 to 79 displayed the highest levels of satisfaction, the ONS found.
The figures come from the first Integrated Household Survey of 200,000 people aged 16 and over between April 2011 and March 2012.
It was conducted as part of the Prime Minister's initiative, launched in 2010, to assess the wellbeing of the nation alongside economic data like GDP.
Glenn Everett, ONS programme director for the Measuring National Well-being Programme, said: "By examining and analysing both objective statistics as well as subjective information, a more complete picture of national wellbeing can be formed.
"Understanding people's views of wellbeing is an important addition to existing official statistics and has potential uses in the policy making process and to aid other decision making."
Asked how satisfied they were with their lives, 75.9% of people gave a response of 7 or more out of 10, while 6.6% answered less than 5 out of 10.
The ethnic group with the highest average anxiety rating was Arab, on 3.7 out of 10. Black people had the lowest average life satisfaction, on 6.7. Some 45% of unemployed people gave a life satisfaction rating of less than 7, compared with just 20% among those with a job.