Gross margin is the job's own result: what the client paid, less what the job itself cost. It's the number that says whether the bid was right. It is not the number that says whether the business made money, because overhead hasn't been paid yet. NAHB's 2026 remodelers' study put the average gross margin at 29.9%; CFMA's benchmarks put general contractors near 15% and specialty trades near 16%, on larger firms with more subcontracted work.
A worked number
Contract $68,000 plus $3,100 in change orders: $71,100 revenue. Direct cost $50,400. Gross profit $20,700, gross margin 29.1%. If overhead runs 23.6% of revenue, the job contributed $16,780 to overhead and left $3,920 of net, about 5.5%.
The mistake it hides
Comparing bid margin to achieved margin only at year end. Bid margin is a promise; achieved margin is what the receipts say, and the gap between them is unbilled extras, lost receipts and labor that was never costed. Contractors who see the gap per job while the job is open can close it; those who see it in the tax return can only regret it.
In Obra
Every project shows expected gross margin as revenue basis minus expected final cost, with the recorded cost as a floor. The profit margins by trade page gives the sourced benchmarks to hold it against.