Start With the Wire List, Not the Picture
The formboard picture shows routing, but the cost lives in the from-to table. Build a line for every circuit: wire gauge, color, spec (for example M22759 or a UL 1007/1015 equivalent), length with a stated tolerance, and what is on each end. A 40-circuit harness with six wire types is really six material purchases and 80 terminations.
Count splices, shielded cable terminations, ground rings, seals and cavity plugs separately, because unused cavities on a sealed connector still need plugs and those are often missing from the customer BOM. Note the harness-level items too: braid or convoluted tubing, heat shrink, labels, cable ties, overmold and backshells. Write down every dimension the drawing does not give you (breakout lengths are the usual gap) before you price anything.
- Circuit count, wire types and total conductor length
- Termination count by terminal and connector family
- Splices, shields, ground rings and cavity plugs
- Sleeving, labels, overmold and backshell hardware
- Missing dimensions and your assumed values
Price Material at the Quantity You Will Really Buy
Wire is bought on spools with minimums, terminals on reels, and connectors often in standard pack quantities from a distributor or the manufacturer. A 50-piece order does not consume a full spool, but you may have to buy one, so decide whether leftover stock goes back to inventory at cost or is charged to the job. Check connector lead times before you commit a delivery date, because a single long-lead housing from Molex, TE Connectivity, Amphenol or ITT Cannon can set the whole schedule.
Add a wire scrap allowance for cut-to-length waste and machine setup, usually a few percent of conductor length, higher for short lengths and exotic wire. Flag copper-sensitive wire so the price can be re-quoted if the quote ages.
Time Each Operation Instead of Guessing Total Hours
Break labor into machine operations (cut and strip, crimp on a bench or automatic wire processor), hand operations (loading terminals into connectors, soldering, taping, sleeving, lacing) and test. Machine setup is a separate line from run time, since a 25-piece lot spends more time on applicator changeovers than on cutting. Hand assembly on the formboard is where the variance is: a harness with tight bundles and shielding takes several times longer than a flat one with the same circuit count.
Use your own routings from similar past jobs, not a rule of thumb per circuit, and keep a separate line for first-article build and documentation.
- Cut and strip, crimp, and seal insertion
- Connector population and pin-by-pin checks
- Formboard lay-up, tying, taping and sleeving
- Continuity and hipot test, plus fixture setup
Try it here, free
Wire Harness Price by Quantity and NRE Calculator
Convert material, labor hours, overhead, test cost, NRE and target gross margin into a unit price and a price-versus-quantity curve.
Add the One-Time Costs Customers Forget to Ask About
Non-recurring costs are where small harness shops quietly lose money on prototype and low-volume orders. Include formboard or nailboard build, test fixture or adapter harness, custom applicator or crimp tooling if the terminal is new to you, programming of the continuity tester, and engineering time to write the work instruction and inspection sheet. Present NRE as a separate line so the customer can see what repeat orders will not carry.
For long-term agreements, state which tooling you amortize into piece price and what happens if the customer leaves before the volume appears.
Quote Terms That Protect Your Margin
Put the quantity break structure on the quote, a minimum order charge, an expiry date, the revision of the drawing you priced and the acceptance standard (for example IPC/WHMA-A-620 Class 2 or Class 3). Say who supplies which parts if the customer consigns connectors, and how shortages or substitutions will be handled. Lead time should start at receipt of complete material, not at purchase order, when long-lead items are involved.
A quote that is silent on these points invites an argument after the first build.
Where Private AI Helps and Where It Does Not
The repetitive part of this process is extraction and lookup: reading the drawing and BOM into a structured circuit list, finding the nearest past harness in your ERP and its actual hours, and flagging parts that were long-lead last time. Netray builds private AI over your ERP and documents that drafts this for the estimator to approve, with every number linked to a source. It is not worth the effort if you quote a handful of repeat harnesses a month, or if a spreadsheet template and a disciplined estimator already turn quotes around in a day.
Frequently asked questions
How long should it take to quote a wire harness?
A simple repeat harness can be quoted in an hour or two when the BOM and routing exist. A new 100-circuit harness with shielding and overmold typically takes a day or more, mostly spent on missing dimensions, connector availability and building the labor routing. Delays usually come from waiting on distributor pricing and from drawings that need customer clarification, not from the arithmetic.
Should I charge NRE on wire harness prototypes?
Yes, as a visible line item. Formboard, test fixture, new tooling and work instruction writing are real costs that a prototype quantity cannot absorb. Many customers accept NRE if it is itemized and credited or waived at a stated production volume. Hiding it in piece price makes low-volume repeat orders look profitable when they are not.
What drawing information is most often missing from harness RFQs?
Breakout and branch lengths, tolerance on overall length, sleeving or braid coverage, label content and placement, and the acceptance class. Customers also frequently omit cavity plugs and seals for sealed connectors. Record each assumption on the quote so a later dispute is about the written assumption instead of memory.
If quote prep eats your estimator's week, send Netray one real drawing package and see a draft circuit list and cost buildup built from your own history.