A futures contract expires. If you want to keep the exposure, you sell the contract that is about to expire and buy a later-dated one — you roll the position. Roll yield is the gain or loss baked into that swap by the shape of the forward curve, and it is separate from any change in the spot price of the commodity.
Over a single roll it is small. Compounded over months or years of holding — which is what commodity ETFs, index products, and long-term futures positions do — it becomes one of the largest drivers of the gap between a fund's return and the headline spot return people see quoted.
When a market is in contango, each later contract costs more than the one expiring. Rolling means selling low and buying high: you give up value on every roll, so roll yield is negative. This is often called negative roll or roll cost.
When a market is in backwardation, each later contract is cheaper than the one expiring. Rolling means selling high and buying low: you capture value on every roll, so roll yield is positive. A long position earns this carry even if the spot price never moves, which is why carry and trend strategies favour backwardated markets.
The total return on a fully collateralised long futures position is roughly the spot price return, plus roll yield, plus the interest earned on the cash collateral.
Take the front-month price and the next contract you would roll into. Express the difference as a percentage of the front-month price, then annualise it by the number of rolls per year (twelve for a monthly contract).
For example, a second month trading 0.5% above the front month is a monthly contango of 0.5%, or very roughly 6% annualised drag before financing. If you expect the spot price to rise less than 6% over the year, a long futures position is fighting a headwind before the directional view even plays out. The roll yield calculator does this arithmetic from two prices you enter.
Roll yield is not a fee and not a prediction. A contangoed market can still rise, and a backwardated one can still fall — the curve shape tells you the cost of carrying the position, not the direction of the next move. It is also not the same as the convenience yield or storage cost directly, though those are what produce the curve shape. And it only applies if you actually roll: a position held to delivery, or closed before expiry, never realises it.
Commodity Hub's forward curve and term-structure tools show the full strip for every tracked market, so you can read the roll cost or benefit directly, and the roll yield calculator turns any two contract prices into an annualised figure. Open the app to check current curves.