United Kingdom and Persian Gulf are almost exactly the same size

The United Kingdom (country) covers about 244,000 km² (94,100 mi²) and the Persian Gulf (gulf) about 243,000 km² (94,000 mi²). Their outlines are laid over each other below at one scale. The Persian Gulf outline is Natural Earth’s, checked against the published area.

244,000km²United Kingdom
243,000km²Persian Gulf

200 km

United Kingdom
Persian Gulf

What fits

Persian Gulf is 100% of the size of United Kingdom.
The measured areas differ by 354 km², less than half a percent: closer than the measurement itself is certain.
Measured in Belgiums: United Kingdom is about 7.95, Persian Gulf about 7.94.

How they differ

Their centres are about 5,350 km apart.
A standard web map misstates the comparison: United Kingdom at 54°N is drawn about 2.9× too large and Persian Gulf at 27°N about 1.3×, so the map shows United Kingdom as 2.31× the size of Persian Gulf instead of 1.00×.
Together United Kingdom and Persian Gulf cover 487,000 km², close to the size of Spain (499,000 km², 2.5% bigger).
United Kingdom's centre is 27.2° of latitude, about 3,030 km, farther north than Persian Gulf's.
United Kingdom ranks 79th of 212 countries by area.
The Persian Gulf is a gulf and ranks 22nd of the 42 seas on sizeversus by area.
Laid out flat, the United Kingdom stretches about 1,210 km north to south and 656 km east to west; the Persian Gulf about 729 km by 933 km.
Our measured 243,000 km² is 3.0% below Wikidata’s published figure of 251,000 km². Published areas of lakes and seas move with the water level and with what is counted, so a few percent is expected.

Who wins on what

Measure	Winner	By
Larger area	United Kingdom	1.00×
Farther north	United Kingdom	27.2° of latitude
Stretched more on a web map	United Kingdom	2.9× against 1.3×

Both against the same yardsticks

Yardstick	United Kingdom	Persian Gulf
Belgium 30,700 km²	7.95×	7.94×
Germany 358,000 km²	0.68×	0.68×
Japan 374,000 km²	0.65×	0.65×
France 548,000 km²	0.44×	0.44×
India 3,151,000 km²	0.08×	0.08×
Brazil 8,473,000 km²	0.03×	0.03×
United States 9,447,000 km²	0.03×	0.03×
Russia 16,980,000 km²	0.01×	0.01×

Each figure is the place's area divided by the yardstick's.

Side by side

	United Kingdom	Persian Gulf
Is a	CountryEurope	Gulfsea on sizeversus
Area, measured	244,000 km²94,100 mi²	243,000 km²94,000 mi²
Area, published	242,000 km²Wikidata	251,000 km²Wikidata
Rank by area	79th of 212countries	22nd of 42seas
Greatest depth	–	90 mWikidata
Latitude range	50°N to 61°N	24°N to 31°N
On the shore	–	8 on the shore

Published figures: Wikidata (CC0). A lake or a sea has no legal boundary: the measured area is that of Natural Earth’s outline, and it is shown beside the published one.

Natural Earth’s outlines of Iran, Saudi Arabia, the United Arab Emirates, Qatar, Kuwait, Oman, Iraq and Bahrain lie within 25 km of the outline of the Persian Gulf. That is what its geometry says, and it is not a statement about who owns the water or where any border runs in it.

Similar in size to United Kingdom

Similar in size to Persian Gulf

More comparisons

Sources and method

Outlines: Lakes and seas: Natural Earth 1:10m physical vectors (public domain), kept only where the measured area is within 10% of the published one. Countries and regions: Natural Earth, 1:10m Admin 0 and Admin 1, public domain.
Boundary: De facto, as drawn by Natural Earth. A lake or a sea has no legal boundary of its own; the outline is a cartographic one.
Area: Measured on the WGS84 ellipsoid from the full-detail outlines, shown rounded. The published figure comes from Wikidata (CC0), fetched 2026-11-11, and is shown beside the measured one.
Drawing: Each outline is projected with an equal-area projection centred on its own centroid, so areas stay true and the two can be laid over each other.
Data built: 2026-11-11

Full method