The average homeowner in England and Wales who sold up last year made around £100,000 more than the amount they had originally paid for their property.
Estate agent Hamptons, which carried out the research, looked at householders selling in 2023 who had bought their homes in the past 20 years.
It found those who had bought a property within this timeframe and sold it last year sold for an average of £102,650 more than they paid.
This was down from a record gross profit of £112,930 in 2022, according to the research, which used Land Registry data.
More than nine in 10, 93%, of those selling a home in 2023 sold for more than they had paid, having owned their home for an average of nearly nine years.
In percentage terms, the average seller in England and Wales last year made a 48% gain, down from 54% in 2022.
The decrease in average gains is partly due to small house price falls last year, but also because more households moved home sooner, researchers said.
The average 2022 seller had owned their home for 9.0 years, but this fell slightly to 8.9 years in 2023.
One in 12, 8%, of those who sold in 2023 had bought their home two years earlier, increasing from 5% of those who sold in 2022 who had made their purchase two years earlier.
Households who had bought in 2021 and sold in 2023 were disproportionately likely to be selling a home in the suburbs or countryside, Hamptons' research indicated, suggesting some of those who had purchased properties in the "race for space" during the coronavirus pandemic had had second thoughts.
Despite the quick turnaround, the average vendor who bought in 2021 still sold their home in 2023 for £56,170 or 23% more than they had initially paid.
Slower house price growth in London in recent years has meant that sellers in Wales are now making bigger percentage gains than Londoners, the report also said.
In 2023, the average home in Wales sold for 53% more than its purchase price, surpassing the London average of 51%.
This reflects the tail end of the housing market cycle, where Wales has had stronger price growth in recent years, in part due to the slower recovery in house prices in Wales following the 2008 financial crash, the report said.
The South Wales Valleys was home to some particularly big percentage gains made by home sellers last year, Hamptons found.
House sellers in Merthyr Tydfil made a 69% or £60,640 average gross profit in 2023.
Those selling in Rhondda Cynon Taff last year made an average gain of 65% or £54,530.
Sellers in Blaenau Gwent, meanwhile, made an average gross gain of 67% £46,390.
The north west of England was also home to hotspots where particularly big house seller gains were made in percentage terms in 2023.
In Manchester, sellers last year made a gross profit of 63% or £84,930; in Trafford they gained 65% – £145,730 – and in Oldham they gained 62% or £66,020.
Higher average property prices mean that London home sellers continue to typically make the biggest gains in cash terms.
The average London homeowner sold their home last year for £204,190 more than they paid for it.
London sellers also tend to have owned their homes for longer, which partly reflects a cohort of would-be sellers whose homes are not currently worth what they paid, researchers said.
Having owned for 10.8 years on average, households in the London borough of Kensington and Chelsea made the biggest cash gains in 2023, with sellers last year achieving an average £680,580 more than they initially paid.
Sellers in the north east of England continued to make the smallest gains in both cash and percentage terms. The average householder who sold in 2023 achieved £40,410 or 33% more than they initially paid.
Aneisha Beveridge, head of research at Hamptons, said: "despite falling house prices last year, 93% of households still sold their home for more than they paid, netting themselves just over £100,000 on average.
"These proceeds are mostly reinvested back into the housing market and go towards the purchase of another home, so they're rarely realised in cash terms.
"However, the numbers illustrate how the scale of historic price growth sheltered movers last year, freeing up cash to cover moving costs.
"Double-digit house price increases since Covid have meant households moving within two years can achieve a higher price than they paid. Historically these are people moving due to a change in circumstances.
"However, the spike in the share of households moving within two years goes beyond that and suggests an unwinding of 'the race for space'.
"Most of these sellers are selling larger homes in the country, often in favour of a move back to the suburbs or city.
"Households rarely move when they're faced with the prospect of selling their home for less than they paid. Generally, the chances of selling at a loss peak within the first few years of ownership.
"But for some Londoners, that stretches back to when parts of the market peaked in 2016. Many households who bought a home between 2014 and 2016, predominantly in prime central London, face selling at a loss, which has reduced sales numbers over the last few years.
"However, we expect prices to start rising in London later this year which may start to unlock some of these moves."
Hamptons used Land Registry price paid data to match homes that were sold in 2023 with their previous purchase. The data looked back 20 years and Hamptons said, if anything, this may understate overall gains, since generally homeowners who have owned a property for more than 20 years will likely have seen stronger house price growth.
The average gains it calculated were across all sales – including homes sold for a profit as well as those sold for a loss.
The gains do not take into account any money spent on properties.
By Vicky Shaw, PA Personal Finance Correspondent
