United States vs United Kingdom population
In 2025 the United States has 4.92× as many people as the United Kingdom: 342 million against 69.5 million. The difference is 272 million.
The United Kingdom would fit inside the United States 4 times over.
How the two compare
In 2025 the United States has 4.92× as many people as the United Kingdom: 342 million against 69.5 million. The difference is 272 million. The United Kingdom would fit inside the United States 4 times over. Together they hold 5% of the 8.19 billion counted here.
Then and now
In 1960 the order was the United States ahead, 181 million to 52.4 million, a ratio of 3.45×. Since then the United States has grown 1.89× and the United Kingdom 1.33×, averaging 0.99% and 0.44% a year.
The lines never cross between 1960 and 2050: the United States stays ahead throughout, and the gap widens by 2050.
Towards 2050
Projected to 2050, the United States reaches 373 million (9.2% more than today) and the United Kingdom reaches 74.9 million (7.8% more). By then the ratio is 4.98× in favour of the United States.
Land and people
Land changes the picture: the United States has 9,147,420 km² and 37 people per km², the United Kingdom has 241,930 km² and 287 per km². The United Kingdom is 7.69× more densely settled.
Behind the totals, fertility is 1.63 in the United States and 1.55 in the United Kingdom; life expectancy is 78.9 against 81.4 years; 18.4% against 19.7% of people are 65 or older. The younger the population, the longer it keeps growing after birth rates fall.
Where the numbers come from
Figures are the World Bank's "Population estimates and projections" series, built from United Nations and national statistics. Values up to 2025 are estimates; 2026–2050 are projections that assume current fertility, mortality and migration trends continue, so they are not forecasts of events such as wars or policy changes. Territories are listed as the World Bank lists them, and a small number of places have gaps in some years.
How the numbers are taken. Total population from the World Bank's population estimates and projections (built from United Nations and national statistics). Values to 2025 are estimates; 2026–2050 are projections that continue current fertility, mortality and migration trends. Sources and limits.