For anchors and fasteners taken to failure: paste the peak loads and get the sample statistics below, including the characteristic value mean − k × s with the k factor from your standard.
Inputs
Nothing you type is uploaded or saved.
Results
Number of tests, n
Mean
Sample standard deviation, s
Coefficient of variation, s / mean
Minimum
Maximum
Characteristic value, mean − k × s
Minimum / design load
Calculated with the free tool at calyx-ai.net/qa/ultimate-load-calculator/ (Quality Tester Solutions LLC).
How it is calculated
Mean is the arithmetic average. s is the sample standard deviation (divides by n − 1, the same as STDEV / STDEV.S in Excel), so it needs at least two results. Coefficient of variation is s divided by the mean. The characteristic value is mean − k × s using the k you enter; the minimum / design ratio is the lowest result divided by the design load you enter.
Where k comes from
This calculator does not choose k for you. The factor depends on the number of tests, the confidence level and the fractile your document requires, so take it from the standard or specification governing the job, or from the engineer of record. The same goes for how many anchors to test and what result is acceptable. Check the current edition with its publisher.
The Fastener & Anchor Pull-Test Report Templates pack has these statistics as an Excel sheet next to a 40-row proof-test report with automatic PASS/FAIL, a calibration log, a kN/lbf/mm/in converter, a printable procedure checklist and a standards index. $49 one-time, from Quality Tester Solutions LLC, the company behind Force-Test pull testers.