EngineerBenchBuilding a machining cost estimate
A machining quote needs more than cycle time multiplied by a machine rate. Material, tooling, setup, attended labor, and expected yield all affect the cost of accepted parts. Enter the required good-part quantity and the operations that contribute to the batch.
Keep machine time and operator time distinct
A machine can run while an operator does other work, but loading, setup, inspection, and manual operations still consume attention. Use the worksheet's time and rate fields to reflect that distinction without double-counting labor already included in a rate. The tool does not derive cycle times from CAD or a toolpath.
Check yield and pricing assumptions
A yield allowance increases the modeled number of attempts needed to deliver the good parts. It is an estimate, not a prediction of actual scrap. Markup and margin use different bases, so confirm which pricing mode matches the way you quote before adding taxes or other charges.
Following batch cost to a unit price
Setup is usually spread across the batch, while material and cycle-related costs often grow with the number of attempts. A larger batch can therefore reduce setup cost per accepted part without changing the machine's cycle time. The yield input increases the modeled attempts needed to deliver the specified good-part quantity; it should reflect the estimating basis rather than disguise an unknown process.
Check what is already included in each rate. A machine rate may include some labor or overhead, so adding the same cost separately would double-count it. Conversely, unattended machine time does not eliminate loading, inspection, and finishing effort. Use cycle times from the planned operation or suitable measurements; the calculator does not derive them from a drawing. Pricing mode then converts estimated cost to a selling price using the selected markup or margin convention. Compare the batch total and unit figure together, especially for small orders where setup dominates. Tooling life, minimum material purchases, and subcontract charges may need explicit entries in the estimate.
Formula
Attempts = good parts / yield. Cost includes material, tooling, setup, machine time, and attended labor.