Interactive 3-2-1 Crack Spread Chart

Purpose

This visualization answers one question that is hard to see clearly with the tools available in the public domain: how does refining profitability today compare to the last forty years?

The crack spread is the gap between what a refinery pays for crude oil and what it earns selling the gasoline and diesel made from it. It is, in plain terms, the refining margin. It matters because it is the hinge between the price of oil and the price you pay at the pump. When the spread is normal, your fuel price tracks the price of crude, the number everyone watches. When the spread blows out, fuel prices detach from crude: oil can fall while the gap widens, and the savings get absorbed before they ever reach you.

So the crack spread is one of the clearest signals of whether cheaper oil will actually become cheaper gas, or won't. The problem is that the long view of it is surprisingly hard to find. Daily values are quoted everywhere. Charts going back a few years are common. But a single, consistent picture stretching back decades, the context you need to judge whether today is normal or extreme, generally sits behind expensive data terminals. This tool exists to put that long view in the public domain, free, so you can judge for yourself where today's refining margins sit against the full sweep of history.

What this page is

Every chart we publish should be something you can check, question, and rebuild yourself. This page documents exactly how we built the crack spread tool: where the data comes from, the formula we used, and the judgment calls along the way. Nothing here is proprietary. The metric is an industry standard and the data is public. Our contribution is assembling the long history into one place. If you wanted to reproduce it from scratch, this page should get you there.

The data source

All prices come from the U.S. Energy Information Administration (EIA), the statistical arm of the U.S. Department of Energy. The data is free, public, and updated weekly. We use spot prices for one crude and the refined products:

• Crude: West Texas Intermediate (WTI) at Cushing, Oklahoma
• Gasoline: NY Harbor conventional and U.S. Gulf Coast conventional
• Distillate: NY Harbor No. 2 heating oil and U.S. Gulf Coast ultra-low-sulfur diesel (ULSD)

We download the full spot price history directly from EIA as a single weekly file. We do not alter, smooth, or adjust the underlying prices.

Step 1 — Understand what a "3-2-1 crack spread" is

The 3-2-1 is the industry's standard rule of thumb for refining margin. The name is the recipe: for every 3 barrels of crude a refinery takes in, it's modeled as producing 2 barrels of gasoline and 1 barrel of distillate. It is a simplification (real refineries make many products in varying proportions), but it's the convention analysts use because it roughly mirrors a typical product slate and lets margins be compared consistently over time.

Crucially, the spread is set by the market, not by refiners. It is the difference between freely traded crude and product prices. Refiners take what the market gives them; they don't dictate it.

Step 2 — Do the arithmetic

We compute the spread in dollars per barrel:

3-2-1 crack = ( (2 × gasoline price + 1 × distillate price) × 42 − 3 × crude price ) ÷ 3

The ×42 converts product prices from dollars per gallon (how gasoline and distillate are quoted) to dollars per barrel (how crude is quoted), since there are 42 gallons in a barrel. We subtract the cost of three barrels of crude from the value of the two-plus-one barrels of product, then divide by three to express the result as dollars per barrel of crude input.

We calculate two versions: a NY Harbor spread (using NY Harbor gasoline and heating oil) and a Gulf Coast spread (using Gulf Coast gasoline and diesel), so you can see both major refining regions.

Step 3 — Assemble the long history

This is the part that doesn't otherwise exist for free. The price series go back decades (NY Harbor to 1986; Gulf Coast diesel begins in 2006), but they live as separate tables. We merge them by date, run the calculation above on every week, and stitch the result into one continuous series from 1986 to the present. The output is the thing that was missing: a single, consistent, decades-long view of the refining margin.

Step 4 — Add context and interactivity

We shade the chart into rough operating zones often cited by analysts (normal, firm, stressed, and rare "acute" territory) so a value isn't just a number but a position relative to history. You can toggle each regional spread, overlay the price of crude itself, and zoom to any time window from three months to the full record. Hover any point to read its exact value and date.

Updating

We refresh the chart weekly. The process is mechanical: download the latest spot price file from the EIA, run our build script, and republish. The calculation and the date ranges update automatically, so the published chart always reflects the most recent EIA release without manual editing.

Honest notes and limitations

We'd rather tell you the edges of this than have you find them.

• This is a long-history proxy, not a trading instrument. Our spread uses WTI crude with conventional gasoline and heating oil because those series carry the deepest history. Some published daily cracks use different inputs (for example, a Gulf Coast spread priced against Louisiana Light crude with RBOB gasoline and ULSD diesel). Those run a few dollars per barrel different from ours. The shape and story over time are what matter here, not matching any single desk's daily quote to the cent.
• The 3-2-1 is a simplification. Real refineries produce jet fuel, asphalt, petrochemical feedstocks, and more, in proportions that vary by facility. The 2-to-1 gasoline-to-distillate ratio is a convention, not a literal description of any one refinery.
• It does not capture crude quality. Our calculation uses WTI, a light crude. Many U.S. refineries are configured for heavier grades, and the margin a specific refiner actually earns depends on the discount or premium of the crude it runs. The published spread is a market benchmark, not any one refiner's realized margin.
• Weekly figures are EIA estimates and can be revised. We use the weekly series for currency and accept that recent points may shift slightly in later releases.
• We did not invent this metric, and we don't claim to have. The 3-2-1 crack spread is an industry standard and every price is the EIA's. Our contribution is assembling the public pieces into the long, continuous history that wasn't otherwise freely available.

Reproduce it yourself

If you want to rebuild this chart, you need only the public EIA weekly spot price series listed above and the formula in Step 2. Merge the series by date, run the calculation on every week, and you'll have the same long history we did. If you get something different from us, we want to know. Tell us, and we'll look.