Decision knowledge
Fewer pages. Better answers.
A small, reviewed library for decisions where the definition, arithmetic and evidence boundary matter. Every published page traces its formulas back to the calculator registry; unsupported combinations stay unpublished.
Knowledge library reviewed 28 August 2026.
Curated collection
Published guidance
The library does not generate a page for every keyword permutation. Each page must add distinct visible value and pass the same indexation gate.
Definition & comparison
Gross margin vs contribution margin: which number answers which decision?
A practical comparison of gross margin and contribution margin, including what each deducts, where they diverge and which decisions each measure can safely support.
Read the guidanceDecision guide
Can I afford to hire someone? A decision sequence, not a revenue guess
A finance-first sequence for testing a hire using workload, fully loaded cost, contribution, break-even revenue and downside cash runway without inventing a universal revenue threshold.
Read the guidanceWorked example
Worked example: why a 10% discount can need 34% more unit sales
A deterministic discount example showing how a 10% price reduction changes per-unit contribution and the whole-unit sales volume required to preserve current total contribution.
Read the guidanceEvidence guide
Australian service-business cash runway: reconciling Xero with CDR bank evidence
A source-aware guide to combining accounting evidence from Xero with consent-bound Australian CDR bank balances and transactions before calculating service-business cash runway.
Read the guidancePublication gate
A combination is not a page by default.
Future problem, business-type, jurisdiction and connector pages remain excluded unless they explain a real source or decision distinction, cite a known product formula, disclose the evidence limits and contain reviewed original guidance.
A valid calculator definition is mandatory; formulas are never duplicated in page templates.
Programmatic drafts, thin copy and unknown source identifiers cannot enter the sitemap or related links.
Connector presence describes an evidence capability, not activation, completeness or freshness.
Review dates, canonical addresses and visible source boundaries are required before indexation.
Want the calculation, not just the definition?
Enter your own values in the public calculator library. The formula remains visible and the result is deterministic for the values supplied.
