A quote for ten assembled boards and a quote for designing a new circuit cover different work. When you ask what a custom PCB costs, separate the engineering from the physical boards. That makes proposals easier to compare and helps you budget for the next revision.

At Insyght we design electronics for connected products and standalone devices. A useful estimate starts with the requirements and the evidence you need at handover. Here is what to put in that brief.

Separate design, fabrication and assembly

PCB design includes selecting components, drawing the circuit and laying out the board. Fabrication produces the bare board. Assembly adds the components. Firmware, enclosure design and testing may be separate work packages.

A fabrication service generally expects manufacturing files. If you have an idea, a breadboard or a list of functions, those files still need to be created. State your starting point when requesting a quote. If you already have a schematic, include its revision and explain which parts have been tested.

What changes the engineering cost

The number of components is only part of the work. A small board can be demanding when it must fit around a battery, measure weak signals or operate at low standby current. Connectors, heat, radio performance and the available enclosure space can change both layout and testing effort.

An existing circuit with clear measurements gives an engineer a different starting point from an unproven sensing concept. Before comparing prices, give each supplier the same requirements:

What the device measures or controls, with the required accuracy or response time.
Supply voltage, power source and operating environment.
Board dimensions, mounting points and connector positions.
Expected prototype quantities and the intended production volume.
Existing design files, firmware and test results.

For the JOGO insole sensor, PCB thickness, battery geometry and the antenna's position under the foot shaped the design. That is why a generic price per component would have told the customer very little about the real engineering effort.

Agree what will be delivered

A handover should identify each deliverable and its format. Depending on the scope, that can include the schematic and layout source files, bill of materials, fabrication files, assembly drawings, component placement data and a test report. Ask which source files are included and agree their use and ownership in the contract.

Also distinguish the files for building the board from software needed to operate it. Firmware development, programming instructions and production test software should be named explicitly. A layout package does not automatically include them.

The KiCad documentation on fabrication outputs illustrates the distinction between board fabrication, drilling and component placement files.

Leave room for measurement and a revision

The first assembled board is an opportunity to measure the actual circuit. Plan checks for the power supplies, current consumption, sensor readings and interfaces. Define the test conditions so results can be repeated.

Discuss how a revision is handled if those checks uncover an issue. Does the estimate include a second layout iteration, another prototype order and a retest? Which changes would be a new requirement? Answering this before the order helps prevent a low initial quote becoming an open-ended project.

Prototype quantities, component availability and assembly setup also affect the physical build cost. A target production unit cost should be assessed separately from the cost of a small engineering batch.

Compare quotes on the same scope

Ask each supplier to separate engineering, prototype parts, board fabrication, assembly and verification. Confirm the revision allowance and which activities depend on your input or a third party. Include a decision point after testing, so committing to a prototype does not silently commit you to volume production.

At handover, use the agreed measurements to decide whether to revise the board, run a pilot batch or investigate an unresolved requirement. Successful power-up alone does not establish every product requirement.

Start with the information you have

You do not need a finished specification to speak with us. Send your sketch, existing board or breadboard photos, together with what it must do and the constraint you are struggling with. We can identify the missing decisions and scope the next phase.

Discuss your PCB design, or read when to move from a breadboard to a custom PCB. If the main uncertainty is whether the idea works at all, rapid prototyping may be the right starting point.