Methodology

The overall estimate answers the question “how much of the oil and liquid fuels that normally left the Persian Gulf via the Strait of Hormuz are still reaching world markets?” We combine observed Persian Gulf and incremental Red Sea loadings with measurable alternative routes. The Persian Gulf contribution is estimated from satellite-observed loading activity rather than from AIS-observed Gulf of Oman exits. The AIS-based Hormuz estimate remains a separate series.

The Persian Gulf contribution uses the estimated loadings and crude/product allocation described in the Persian Gulf Loading Methodology.

We add the incremental Saudi Red Sea offset calculated from its trailing 14-day satellite signal, the Fujairah pipeline offset and other incremental overland offsets. These components are defined in their respective methodologies. Alternative-route components include only volumes above their own pre-war baselines, avoiding double-counting exports that already bypassed Hormuz before the war. Daily chart bars combine the daily Gulf loading estimate with these offsets. The average line combines the seven-day Gulf loading estimate with the same offsets; it is not a second moving average of the combined daily bars.

The pre-war baseline is 20,000,000 barrels per day: 15,000,000 barrels per day of crude oil and condensate and 5,000,000 barrels per day of petroleum products. These are rounded working estimates based on the IEA’s full-year 2025 exports through the Strait of Hormuz, rather than total two-way traffic or a single quarter. The IEA reports 14.95 mbpd crude and condensate, 4.93 mbpd products and 19.87 mbpd total. LNG is excluded. ¹

Percent of normal is the combined estimate divided by 20,000,000 barrels per day and multiplied by 100. It can exceed 100 percent if implied Gulf flows and incremental alternative exports together exceed the pre-war baseline.

We infer 'flow' from observed loadings because in the absence of rising oil on water inside the Gulf, there is nowhere else for this oil to go. There is currently no evidence of rising oil on water in the Gulf.

And conceptually, tankers loading inside the Persian Gulf at this point in the war entered through the strait since the war started, which implies that strait transit is not an issue for them in the absence of deteriorating conditions after entry.

Further, at prior inflection points in the war such as the signing and later collapse of the MoU, visible Persian Gulf loadings rose and fell exactly as you would expect if this represented a continuous in and out flow dependent on strait conditions.

Thus observed loadings strongly infer export to world markets outside the strait.

Flows through the Strait of Hormuz are estimated downstream, after tankers have entered the Gulf of Oman, rather than from vessel signals inside the strait itself. Most tanker traffic near the strait is now dark, and a significant share of the oil reaching market is transferred between vessels in the Gulf of Oman. Recipient tankers generally resume transmitting AIS before leaving the Gulf of Oman, making laden eastbound exits a more complete observable signal than direct crossings of the strait.

For each reporting period, estimated cargo aboard laden tankers exiting the Gulf of Oman is summed and converted to an average daily flow. This gross Gulf of Oman flow includes exports loaded outside the Strait of Hormuz and therefore requires two deductions. Fujairah throughput is deducted at 1,800,000 barrels per day, as established in the Fujairah methodology. Oman exports are deducted at a working sustainable rate of approximately 1,160,000 barrels per day. This consists of 843,700 barrels per day of crude and condensate exports and approximately 313,000 barrels per day of liquid petroleum-product exports. ² The product estimate includes LPG, aviation fuel, diesel, naphtha and other liquid petroleum products, while excluding petroleum coke because it is a dry bulk commodity and does not contribute to the tracked tanker signal. ³ Together, Fujairah and Oman account for a working deduction of approximately 2,960,000 barrels per day from gross Gulf of Oman tanker exits.

The initial implied Hormuz flow is the gross Gulf of Oman exit flow minus this combined outside-Strait deduction, with a floor of zero. Short-term discrepancies can arise from storage draws, loading schedules and normal volatility in Fujairah or Oman exports, but the sustainable average over longer periods provides an estimate of the flow that must have originated inside the strait.

Estimates can be revised when tankers that remained dark through the Gulf of Oman later appear near southeastern Sri Lanka or the Strait of Malacca. A laden eastbound tanker detected in either monitoring area is flagged for manual review when its reported last port is implausible or lies in the Persian Gulf or Gulf of Oman, or when the vessel's name contains “Prosperity.” An implausible last port includes a location ahead of the vessel on its eastbound voyage rather than a credible origin. Review considers the vessel's track, draught, direction, reported voyage information and other available evidence. If the vessel is confirmed or reasonably suspected to have carried cargo originating in the Persian Gulf or Gulf of Oman, its estimated cargo is assigned to the most likely earlier Gulf of Oman exit period and the affected Hormuz flow estimate is revised.

We did not start tracking until June 4th, and don't yet have access to historical AIS data prior to that so the Hormuz flow numbers for prior dates are inferred from public reporting of Kpler data. The split between crude and product on those earlier dates is assumed to be 75% crude and condensate and 25% products, matching our rounded 15 mbpd / 5 mbpd baseline based on the IEA’s full-year 2025 export estimates. The reported total flows are unchanged. ¹

The Yanbu and Saudi Red Sea offset measures the increase in Saudi oil and liquids exports from Red Sea terminals relative to normal pre-war activity. It is an incremental offset, not a measure of total Red Sea exports. The pre-war baseline is 1,720,000 barrels per day. ⁴ This consists of 750,000 barrels per day of crude and condensate exports from Yanbu North and Yanbu South/Al Muajjiz ⁵ and 970,000 barrels per day of refined-product exports from Saudi west-coast refineries ⁶, based on Kpler estimates for 2025. The combined figure is consistent with the IEA's independently reported 2025 average of approximately 1.7 million barrels per day of exports from Saudi Arabia's western ports. ⁴

Current exports are estimated from repeated Sentinel 1 and 2 observations of covered liquid-export loading sites. Each usable capture is analyzed for loading tankers and a length, deadweight tonnage, and barrel capacity is assigned. The estimated barrels represented by those vessels are summed into a “barrels observed loading” signal.

The signal is not treated as a direct count of exported barrels because the same vessel may appear in more than one image and some loading activity occurs between satellite passes.

Instead, we compare the signal to its 2025 baseline, which is the average of barrels observed loading on each satellite pass in 2025, counted using an identical method for a like-for-like comparison. We take the ratio of the current signal to the 2025 signal and multiply it by the pre-war baseline of 1.7 mbpd. Tested on April / May numbers, this method yielded implied exports of 4.6 mbpd, within 10% of Kpler’s ~5mbpd total liquid exports estimate for the Red Sea.

East–West Pipeline throughput is not used directly as an export measure. Crude delivered to a west-coast refinery is an intermediate movement and is counted only if the resulting product is subsequently loaded for export, preventing the same barrel from being counted twice. Domestic coastal deliveries are excluded.

In terms of the split between refined products and crude, we know based on public reporting of Kpler’s refined-product estimate, that product exports averaged approximately 1,020,000 barrels per day in January through May 2026, only about 50,000 barrels per day above Kpler's 970,000-barrel-per-day average for 2025. ⁷

The refined-product contribution to the offset is therefore capped at 50,000 barrels per day, with the remainder of the estimated Red Sea offset attributed to crude and condensate.

The Fujairah offset measures only the incremental crude exports made possible by increased use of the Abu Dhabi Crude Oil Pipeline (ADCOP, or Habshan–Fujairah pipeline) after the outbreak of hostilities. It is not a measure of total activity at the Port of Fujairah.

The pre-war baseline is 1,000,000 barrels per day, based on the IEA's estimate that the UAE transported about 1 million barrels per day of crude through ADCOP in 2025. ⁴ Wartime throughput is assumed to be 1,800,000 barrels per day, the reported upper operating rate of the pipeline. ⁴ This assumption is corroborated by the IEA's estimate that Fujairah crude exports reached 1.8 million barrels per day in April 2026 ⁸ and Kpler's estimate of 1.82 million barrels per day of terminal loadings that month. ⁹

The estimated incremental Fujairah offset is therefore 800,000 barrels per day: 1,800,000 barrels per day of wartime throughput minus the 1,000,000-barrel-per-day pre-war baseline. Short-lived loadings above pipeline capacity are excluded because they may include withdrawals from the Al-Mandous storage complex and do not establish sustainable pipeline throughput.

The other offset is fixed at 100,000 barrels per day and represents Iraqi fuel oil moved overland by truck through Syria to the Mediterranean port of Baniyas for export. This route began operating after the disruption of normal Gulf exports and therefore represents an incremental alternative to flows that would otherwise depend on the Strait of Hormuz. ¹⁰

Iraq also exports crude through the Iraq–Türkiye pipeline to Ceyhan, but current throughput on that route is not treated as an incremental wartime offset because limited northern exports were already operating before the disruption and demonstrated current flows have not materially exceeded that baseline. ¹¹ Proposed expansions and future pipeline targets are excluded until additional export volumes are observed.

For Persian Gulf loading activity we mapped 130 major oil and petroleum-product loading positions across 67 active observation targets inside the Persian Gulf. The monitored inventory covers 95+% of pre-war exports.

Sentinel-1 synthetic-aperture-radar and Sentinel-2 true-color imagery are collected for every available pass over each target. Each usable capture is analyzed for tankers loading at the mapped terminal, and each observed vessel is assigned an estimated length, deadweight tonnage, barrel capacity and product vs crude classification based on the nature of the loading site.

For each site we then establish a pre-war baseline of “average barrels being loaded” on each satellite pass from January to December 2025. Then for each post war period we divide the current observation (or average of a set of observations in the case of 7d trailing average) by that baseline to get a “percent of normal loading activity” across all sites.

This is then scaled by a 20 mbpd pre-war export baseline, rounded from the IEA’s full-year 2025 estimate of exports through the Strait of Hormuz, to infer a mbpd loading activity estimate. The working baseline is 15 mbpd crude and condensate and 5 mbpd products; observed loading activity is still classified by loading-site cargo options. ¹

Inbound empty-tanker capacity is a leading indicator of future Strait of Hormuz loading and export potential. The signal includes oil and liquids tankers crossing the Gulf of Oman entrance line from east to west with an estimated cargo of zero barrels.

Each qualifying vessel contributes estimated carrying capacity equal to deadweight tonnage multiplied by seven barrels per tonne. Crude and product capacity are classified using the same vessel and cargo rules as the outbound Hormuz series; LNG and generic gas tankers are excluded.

We then deduct known tanker-capacity requirements associated with Fujairah and Oman exports using the same crude and product assumptions as the downstream Hormuz methodology, producing an implied Strait/STS-bound capacity signal with a floor of zero.

This is a leading capacity indicator rather than a direct forecast of next-day exports: vessels may wait, load several days later, or remain within the region, so trailing averages are more informative than individual daily observations.