Every number has a fork in it.

• Average order valueThe easiest metric in ecommerce to calculate and one of the easiest to calculate four different ways without noticing.$45.71
• Repeat purchase rateThe metric that decides whether you have a business or a customer acquisition habit, and the one most often computed on a window too short to show it.24.2%
• Days sales outstandingHow long your money takes to arrive, expressed as a single number that no individual client matches.46.00
• Cash runwayHow long you last at the current rate, and the reason the honest version of this number is so much shorter than the flattering one.45.00
• Donor retention rateThe sector's headline health metric, and the one most distorted by the duplicate records nobody has time to merge.58.1%
• Revenue concentrationA year that grew while becoming dependent on eleven households is a worse year than it looks.52.0%
• No-show rateA rate that counts three different events, costing a session, a phone call and nothing respectively.11.4%
• Utilization rateThe metric that decides whether you need more hours or the same hours somewhere else, and the one most often computed against a denominator that guarantees a flattering answer.78.0%
• Contribution marginThe number that decides whether a product can afford to be advertised, and the reason a 59% gross margin can be negative.214
• Dead stock shareThe share of your stock value that has stopped moving, computed from when things actually last sold rather than from what the stock sheet claims.31.0%
• Survey completion rateReported as a health metric, and actually the single best predictor of whether your headline finding will survive contact with reality.71.2%
• Customer acquisition costEvery ad platform reports a version of this, and the versions sum to more customers than exist.$117
• Gross marginThe margin most systems report, and the one that hides every variable cost of actually selling something.54.0%

Each figure above is taken from a finished project on this site rather than written here, so opening one shows you the calculation, its filters and the rows behind it. A metric with no worked project does not get a page.