2026-11-05 · 4 min read
Three estimate mistakes that quietly eat your margin
The math mistakes contractors make on estimates — and how to catch them before they reach the customer.
Confusing markup with margin
A 25% markup on a $1,000 cost gives a $1,250 price and a 20% gross margin. If you needed a 25% margin, the price should have been $1,333. Know which number you're actually targeting.
Forgetting change orders
Scope changes that aren't recorded become margin you never see. Agree on changes in writing before the work happens, and keep the record attached to the job.
Estimating from a competitor's price
A copied price includes someone else's costs, tax treatment and mistakes. Price from your own complete cost estimate, then update your templates from actual job history.
The fix
Use a calculator that separates cost, margin and price, compare every estimate to actuals when the job closes, and build your templates from your own numbers.
Put it to work
Import your customers into a free unlimited-contacts CRM and put a next action on every live lead. No card, no per-seat fees.