About TwinCalc
An informational statistical tool based on published research — not a clinical service.
An informational, research-based statistical tool.
TwinCalc is an informational, research-based statistical tool. It applies a multiplicative model — derived from peer-reviewed epidemiology — to a 1.5% global twin baseline, capped at 25%. Every multiplier is documented on the methodology page with the studies behind it.
Read the full model on our methodology page. TwinCalc is free, contains no advertising, and sells nothing.
Where the line is, plainly.
We want to be precise about our scope. TwinCalc is:
- • Not medical advice. The calculator cannot diagnose, predict, or replace a clinical consultation.
- • Not personally reviewed by any physician. No named doctor or clinician has examined or validated the content. Editorial decisions are made using public, peer-reviewed sources.
- • Not a substitute for a professional consultation. Talk to a qualified healthcare provider for guidance on your situation.
- • Not affiliated with any clinic, hospital, health authority, or pharmaceutical brand. We sell nothing and accept no commercial sponsorship.
Public datasets and peer-reviewed journals.
The model and articles draw on public datasets and guidelines from the National Institutes of Health (NIH National Vital Statistics), the American Society for Reproductive Medicine (ASRM), the American College of Obstetricians and Gynecologists (ACOG), and the World Health Organization (WHO), plus indexed journals (Human Reproduction, Twin Research and Human Genetics, Obstetrics & Gynecology, Reproductive Sciences).
Every multiplier and assumption is documented on the methodology page, with the underlying study referenced.
How we write.
- • Cite every factual claim. Each multiplier links to the underlying research.
- • Be explicit about uncertainty. Where evidence is mixed, we say so.
- • Stay informational. We do not give individualized medical advice.
- • Update transparently. Every page carries a last-updated date and corrections are acknowledged on the page.
Editorial principles
How we write — and what this tool is not.
Peer-reviewed sources
Every factor cites peer-reviewed literature: NIH, ASRM, ACOG, WHO, indexed journals.
Transparent methodology
Multipliers, cap, limitations — all documented on the methodology page.
Clear scope, no medical advice
Informational tool grounded in population data. Does not replace a qualified healthcare provider.
Contact
Questions, corrections, or methodology feedback are welcome. We read every email.