1. Define the scope
List material type, dimensions, quantity, finish, tolerances, delivery, installation and any customer-supplied parts. Ambiguous scope is where estimates get burned.
2. Build the material takeoff
Use cut lists and project-material calculators to estimate full stock lengths, then add realistic waste, freight and supplier cut charges.
3. Estimate total labor
Include measuring, layout, cutting, fit-up, tack-up, welding, grinding, handling, cleanup, delivery and admin. Arc time is only one slice of the job.
4. Add consumables and gas
Wire/rod, contact tips, discs, saw blades, shielding gas and PPE wear all cost money even when each individual item seems small.
5. Add overhead and profit separately
Overhead keeps the business running; profit rewards the risk and capital. Do not confuse the two.