The Stocks-to-Use Ratio, Explained

One number shows up again and again in USDA reports and on this site's Market Reports page: stocks-to-use. It's one of the best single predictors of how much a bad harvest is going to move prices — and it's simpler than it sounds.

What it actually measures

Stocks-to-use compares two things for a given marketing year: how much of a commodity is left in storage at the end of the year (ending stocks), and how much gets used in total over that year (domestic consumption plus exports, together called total use). Divide the first by the second and multiply by 100, and you get a percentage — the world's leftover cushion, expressed as a share of a full year's worth of demand. A stocks-to-use ratio of 25% means there's roughly three months of consumption sitting in storage once the marketing year ends.

Why a thin cushion means bigger price swings

A high stocks-to-use ratio means a large buffer is sitting in warehouses and silos — if a harvest disappoints, buyers can draw down existing stocks instead of bidding the price up sharply to ration scarce supply. A low ratio means there's very little slack: the same size shortfall has to be absorbed almost entirely through higher prices, because there's no reserve to fall back on. This is the single biggest reason an identical percentage crop-loss headline can barely move one commodity's price while sending another sharply higher — it depends on how much cushion existed before the bad news hit, not just on the size of the loss itself.

A real example

USDA's own PSD Online data (see the Market Reports page for the current numbers) put world wheat stocks-to-use at 26.7% for the 2025/26 marketing year, projected to edge down to 26.4% for 2026/27. That's a small move — under a percentage point — but it's the difference between "roughly the same cushion as last year" and "very slightly tighter," and traders watch that direction of travel as closely as the absolute level.

What moves the ratio itself

Production shocks are the obvious driver — droughts, floods, an early frost. But demand growth matters just as much on the other side of the ratio: a growing population, biofuel mandates that pull more corn or vegetable oil into fuel instead of food, and rising meat consumption (which pulls more grain into animal feed) all increase total use even when production stays flat, which lowers the ratio just as surely as a bad harvest would. Policy adds a further wrinkle - an export ban keeps supply inside the exporting country and doesn't change the world production number, but if it also curbs how much gets used, the ratio moves too. And some countries, China in particular, hold large strategic grain reserves for food-security reasons that aren't available to the international market even though they count in the world total - worth keeping in mind when a "world" stocks-to-use number looks more comfortable than the market it's actually describing.

Where to see it on this site

The Market Reports page lists the current stocks-to-use ratio, and the change from the prior marketing year, for every commodity USDA's PSD Online database tracks with a reliable global figure - not just wheat, corn and soybeans, but many of the softs, oils and minor grains covered elsewhere on this site too.

Next article: What Is a Marketing Year?