What the US-Iran shipping disruption actually cost: Brent, bunker and diesel

The Reshoring Initiative 2025 Annual Report says, on page 16: “The U.S.-Iran conflict is disrupting shipping routes and adding uncertainty to global supply chains.” The report gives no price figures for that sentence. This article supplies them for three fuels that move freight: crude oil, ship fuel and truck diesel.

The dates come from the US Energy Information Administration (EIA), which has described traffic through the Strait of Hormuz in each monthly Short-Term Energy Outlook (STEO) since March 2026. The sentences below are EIA's, copied exactly. We use Feb 28, 2026 as the start because EIA does, and we take the last reading before it as the baseline.

Each row is one series from our API, as returned: the last reading before Feb 28, 2026, the highest reading since, and the latest when we pulled the data on Nov 14, 2026.

Three things stand out. Rotterdam marine gasoil (MGO) rose the most in dollars and peaked late: $1,530.50 on Sep 16, 2026, against $718.04 on Feb 27, 2026. The highs did not come together: Singapore VLSFO peaked in March, Brent in April, Fujairah VLSFO in June, and MGO and US diesel in September. And no series is at its high now. On the latest readings Brent was 18.2% below its high, Singapore VLSFO 23.0% below, Rotterdam MGO 18.9% below and US diesel 6.2% below.

The Fujairah series behaved differently from the other ports in June. On Jun 13, 2026 our Fujairah VLSFO reading was $1,275.00 a ton, $551.50 above Singapore ($1,275.00 − $723.50). On Feb 27, 2026 the two were $3.46 apart. We report the reading as it is in the series. Live port prices are on the Fujairah, Singapore and Rotterdam pages.

The charts put four series on one scale by indexing each to its average for the week of Feb 23, 2026, the last full week before Feb 28. A value of 200 means double that week's price. Brent is drawn in both panels so they can be compared.

In words: prices rose through March, eased from late May into early July, rose again from mid-July to September and October, and fell in the first two weeks of November. Brent was $70.90 on Jul 2, 2026, below its Feb 27, 2026 reading, two weeks after the Jun 18 memorandum EIA describes. Diesel did not return to its February level at any point: its lowest weekly price after Feb 28 was $4.578, in the week of Jul 6, 2026.

EIA reports the Brent spot price. Our BRENT_CRUDE_USD series follows front-month futures quotes. They agreed at the start: EIA's March 2026 STEO puts spot Brent at an average of $71 a barrel on Feb 27 and $104 on Mar 9, 2026, and our series reads $71.82 and $104.28 on those days. They then separated. EIA's May 2026 STEO says spot Brent reached a high of $138 on Apr 7, 2026; our series averaged $109.99 that day.

So the spot price EIA reports rose more than the futures-based series, most of all in April, September and October. Anyone quoting “the Brent price” for this period should say which one. The live futures-based quote is on the Brent crude oil price page.

A ship buying VLSFO in Singapore paid $555.02 more per metric ton on Mar 20, 2026 than on Feb 27, 2026, and $309.12 more on Nov 12, 2026 ($822.00 − $512.88). For Rotterdam MGO the difference was $812.46 a ton at the high and $522.46 on Nov 12, 2026.

We do not turn that into a cost per voyage or per container, because that needs a fuel quantity carriers do not publish. Maersk's BAF appendix gives the structure: “BAF = Maersk Trade Factor x Fuel Price”, where the trade factor is tonnes of fuel per 40-foot container. Under that formula a change in the fuel price moves the charge by the trade factor times the change. With your own trade factor or voyage consumption, the bunker adjustment factor calculator does the arithmetic. Port-by-port prices are on the bunker fuel prices page.

EIA's weekly US No 2 diesel retail price was $6.127 in the week of Nov 9, 2026, $2.318 above the week of Feb 23, 2026 and $2.290 above the week of Nov 10, 2025 ($3.837). Our DIESEL_RETAIL_USD weekly series matches EIA's for every week used here.

Per mile: the American Transportation Research Institute (ATRI) reports that truck-tractors averaged 7.43 miles per gallon in 2025 (Operational Costs of Trucking, July 2026 update). At that fuel economy the rise since the week of Feb 23, 2026 is $2.318 ÷ 7.43 miles per gallon = $0.312 a mile, or $312 per 1,000 miles. At the September high it was $2.720 ÷ 7.43 = $0.366 a mile. These are OPA calculations for an average truck; a fuel surcharge can pass some of it to the shipper, with a lag. The truck versus rail article works through fuel per load and surcharge timing. Current prices are on the live diesel price and diesel prices pages.

Stocks are part of the diesel picture. EIA's Weekly Petroleum Status Report summary for the week ending Nov 6, 2026 says: “Distillate inventories increased 4.1 million barrels, 8% below the five-year average.” Where the missing barrels went is the subject of our Strait of Hormuz inventory check.

The report says shipping routes are being disrupted. The prices of the fuels that move freight are consistent with that: all six series rose after Feb 28, 2026, the date EIA gives for the effective closure of the strait, and all six were still above their earlier level on the latest reading, by 33.6% for Brent, 60.3% for Singapore VLSFO, 72.8% for Rotterdam MGO and 60.9% for US diesel.

What the data does not show: how much of each rise came from the strait and how much from other things that changed over the same period, such as refinery output, demand and stock levels. It does not show freight rates, transit times or cargo volumes, and it does not show who ended up paying. Prices this far above February are a cost; they are not at the peak, and the timing alone is not proof of cause.

The verdict would weaken if the series fell back to their February levels while EIA still described flows through the strait as constrained, or if they stayed high after EIA reported normal traffic.

The figures on this page are static, copied from the API on Nov 14, 2026. This script pulls the same daily history and prints the last reading before Feb 28, 2026, the high since and the latest for four of the codes.