Strait of Hormuz oil flow: estimates range from 7.4 to 13 million barrels a day

Ship counts are the lowest numbers because they rely on the Automatic Identification System, the transponder signal that satellites pick up. The JMIC warns that ships transiting "with AIS-on" face elevated risk and directed radio hails, and reports persistent GPS jamming and spoofing across the area. Many crossings therefore do not show up on public maps. IMF PortWatch says the same in its notes on conflict areas.

Barrel counts are higher because firms such as Kpler and Vortexa combine transponder data with satellite imagery, port loadings and cargo records. Their numbers are preliminary and move from week to week: Kpler counted 49.2 million barrels of crude out through the strait in the full week before September 20, and 33.7 million in the first six days of the following week, on 19 tankers.

Regional export totals are higher still because they include oil that never enters the strait: Saudi crude piped west to Yanbu on the Red Sea, and Emirati crude piped to Fujairah on the Gulf of Oman. That is why the IEA's 13 million barrels a day for August and Kpler's 12.8 million for September are not strait flows. The Energy Secretary's figure of almost 13 million a day refers to the strait itself and is well above Kpler's; no method was given with it.

The fair reading on September 29: on Kpler's count, crude is leaving through Hormuz at about half the 15 million barrels a day the IEA measured for 2025, Middle East crude exports by all routes are about two-thirds of February's, and the numbers can swing by millions of barrels from one week to the next.

The strait joins the Persian Gulf, on the left of the image, to the Gulf of Oman and the Arabian Sea, on the right. NASA describes it as only about 21 miles wide at its narrowest point and roughly 96 miles long. Every tanker loading in Kuwait, Iraq, Qatar, Bahrain or at the Saudi and Emirati terminals inside the Gulf has to pass through it.

Ships now use two routes. The JMIC's advisories describe a "northern Iranian-controlled route" and a southern corridor along the Omani coast, where U.S. naval forces coordinate transits. MARAD, the U.S. Maritime Administration, keeps an advisory in force for the Persian Gulf, the strait and the Gulf of Oman: 2026-011, which replaced advisory 2026-004 and runs until March 8, 2027. The earlier version told U.S.-flagged ships to plan their voyages with the Navy's shipping coordination center and to stay as far as possible from Iranian waters.

In 2024 the U.S. imported about 0.5 million barrels a day of crude through Hormuz, 7% of its crude imports and 2% of its oil consumption, according to the EIA. The link to the pump is price, not supply. Brent, the world benchmark, went from $71.32 a barrel on February 27 to a 2026 high of $138.21 on April 7, and was $114.89 on September 22, the latest EIA daily figure. On our calculation, that September level adds about $1.04 to the crude in every gallon compared with February, roughly two-thirds of the $1.54 rise in the national average for regular.

Most of the rest is refining. Wholesale gasoline on the Gulf Coast rose from $1.968 a gallon on February 27 to $3.891 on September 22, faster than the pump price, and pump prices follow wholesale with a lag. The same squeeze hits diesel harder: the Gulf exported a lot of ready-made diesel, and the IEA says those exports were "just over a quarter of pre-war levels" in August. Our price breakdown splits this week's gallon into crude, refining and taxes, and the diesel page has the same figures by region.

The cheapest gas is still along the Gulf Coast: Texas averages $3.929 and Houston $3.86. The dearest is on the West Coast, with California at $6.003 and Los Angeles at $5.98. The Midwest had the biggest weekly jump, 29.5 cents to $4.386.