Quality calculator
Inspection Sampling Calculator
Estimate how much inspection is required and how likely the sample is to catch a defect at the expected defect rate.
What this calculator does
- Estimate inspection load and the probability of detecting at least one defect in a sampled lot.
- Use when choosing sample size for receiving inspection, containment, or process verification.
- Estimate inspection load and the probability of detecting at least one defect in a sampled lot.
Formula used
- Sampling rate = sample size ÷ lot size
- Detection probability = 1 − (1 − defect rate) ^ sample size
- Inspection hours = sample size × seconds per inspection ÷ 3,600
Inputs explained
- Lot size: undefined
- Sample size: undefined
- Expected defect rate: undefined
- Inspection time: undefined
How to use the result
- Use when choosing sample size for receiving inspection, containment, or process verification.
- This is a planning calculator. Validate assumptions against your process data before using the result as a final quote, schedule, or engineering decision.
Common questions
- Which inputs usually drive the inspection sampling result? lot size, sample size, expected defect rate, and inspection time usually have the biggest effect. When one of those assumptions changes, rerun the calculator and compare the new % result before updating the plan.
- What does the inspection sampling calculator do? Estimate inspection load and the probability of detecting at least one defect in a sampled lot.
- What inputs do I need for the inspection sampling calculator? You need lot size, sample size, expected defect rate, and inspection time. Use measured values from your line, quote package, supplier data, or current production plan whenever possible.
- How should I interpret the inspection sampling result? Treat the % output as a planning estimate for quality work. Compare it against process history, quoted assumptions, and operating limits before making final decisions.
Last reviewed 2026-05-12.