Gross margin is price minus direct cost. Net margin is what remains after overhead too. Owners and accountants usually talk in margin. Estimators often work in markup.
Example: a job sells for 125 and costs 100. The gross margin is 25, which is 20 percent of the price. The markup on the same job is 25 percent.
To hit a target margin, divide cost by one minus the margin. Do not multiply cost by one plus the margin. Review margin by job type after closeout. The review shows which kinds of work earn money.