To work out how much margin you need to trade a commodity market, you divide the notional value of your position by its margin factor. Say, for example, that you want to open an oil position worth $5000 and oil has a margin factor of 20%. You’d need (20% of $5000) $1000 as margin.
How you calculate the notional value of your trade depends on how you’re trading the commodity. With CFDs, it’s the number of contracts you’re trading multiplied by the value of each individual contract.
Learn more about how to trade commodities.