WHAT ARE YOUR ESTIMATED HIV ODDS?

Not a basic questionnaire. A state-of-the-art Bayesian risk modeling system that generates a full 6-page personalized analysis of your HIV transmission probability from a single sexual encounter.

Proprietary logic. Regularly updated. A sophisticated HIV risk modeling system.

WHY THIS ISN'T JUST ANOTHER HIV CALCULATOR

Most HIV risk tools ask a few questions and return a vague label. HIV Risk Report is fundamentally different. You don't just get a number. You get a 6-page personalized analysis that walks you through the entire calculation, explains what drove your result and gives you clear next steps.

Behind the report is our proprietary engine, which uses Bayesian probability modeling. Bayesian methods are widely used across medical and epidemiological research. Our engine applies this framework to calculate a personalized transmission probability for your scenario.

The model is regularly reviewed and updated as relevant new evidence becomes available. Model assumptions, epidemiological datasets and risk modifiers are regularly reviewed against the relevant published evidence. This isn't a static lookup table. It's a living statistical system.

Our methodology sits at the intersection of established HIV science and emerging AI-assisted health analysis, allowing evidence to be applied with greater context and specificity.

Bayesian Probability Framework Proprietary Logic Regularly Updated Peer-Reviewed Data Sources Multi-Factor Modeling Country-Level Epidemiology AI-Assisted Analysis

Standard HIV Calculators vs. HIV Risk Report

HIV Risk Report takes a different approach from conventional HIV risk calculators. Here's the difference between a basic questionnaire and a state-of-the-art Bayesian modeling system.

Standard Calculators

  • Return vague labels: "low", "medium", "high"
  • Use static lookup tables with no nuance
  • Ignore country-level epidemiological context
  • Don't account for partner treatment status
  • No calculation transparency, just black box output
  • One-size-fits-all approach

HIV Risk Report (Bayesian Engine)

  • Returns a personalized percentage and 1-in-X estimate
  • Proprietary Bayesian model with multi-factor analysis
  • Full 6-page PDF report, not just a single number
  • Incorporates country-specific prevalence and treatment data
  • Accounts for ART, viral suppression and partner risk factors
  • Full step-by-step calculation breakdown in your report
  • Regularly reviewed and updated against peer-reviewed literature
  • Every estimate is unique to your specific encounter

Inside the Bayesian Risk Engine

Our proprietary engine doesn't just classify your risk. It calculates it. The system processes your encounter through multiple statistical layers, each incorporating different dimensions of HIV transmission probability. The result is a personalized estimate that reflects the specific combination of factors present in your scenario.

The Bayesian framework means the model starts with a prior probability (based on your partner's estimated HIV status and country-level data) and updates it with each piece of encounter-specific evidence you provide (exposure type, protective measures, biological factors) to arrive at a posterior probability unique to you.

Factors Processed by the Engine

Exposure Type & Directionality

Anal, vaginal and oral exposure each carry different baseline transmission probabilities. The engine further differentiates by insertive vs. receptive role, as tissue exposure and biological pathways differ significantly.

Partner HIV Probability (Prior)

The Bayesian prior is constructed from known partner status, country-level prevalence data, demographic factors and relevant risk indicators to estimate the probability HIV was present in the encounter.

ART & Viral Suppression Modeling

When relevant, the engine incorporates treatment coverage and viral suppression rates, accounting for the dramatic reduction in transmission probability associated with effective antiretroviral therapy.

Protective Measures

Condom use and PrEP are modeled as risk-reducing multipliers with values derived from clinical trial data, applied conditionally based on the specifics of your encounter.

Biological & Contextual Modifiers

The model accounts for factors such as ejaculation, mucosal integrity, circumcision status and inflammation, each calibrated against peer-reviewed meta-analytic evidence.

Country-Level Epidemiology

Rather than relying on a single global average, the engine pulls country-specific HIV prevalence and treatment data to contextualize your estimate within the relevant epidemic profile.

Your final estimate is expressed as both a percentage and a "1 in X" figure, with a full breakdown of how each factor contributed to the result. This is an educational statistical estimate, not a diagnosis. Testing is required to determine HIV status.

How It Works

Your personalized HIV Risk Report is generated in under 30 minutes.

  1. Describe your encounter: Confidentially enter the details: exposure type, partner context, location, protective measures and relevant biological factors.

  2. Bayesian engine processes your data: Your inputs are run through our proprietary multi-factor model, constructing a prior probability and updating it with each encounter-specific variable.

  3. Receive your 6-page report: Get a comprehensive personalized PDF containing your calculated probability, the full step-by-step calculation breakdown, contextual explanations of what your number means and clear next-step guidance including testing timelines.

Why Trust the Results?

Built on rigorous statistical methodology and peer-reviewed data.

  • Bayesian statistical framework: The same class of probabilistic reasoning used in clinical diagnostics, applied to HIV transmission modeling with encounter-specific detail.

  • Regularly updated model: Risk multipliers and data sources are regularly cross-referenced against new peer-reviewed publications. This is a living system, not a static tool.

  • Full calculation transparency: See how your number was derived. Every factor, every multiplier, every step. View our Risk Engine methodology.

  • Encounter-specific detail: No two estimates are the same. Your result reflects the unique combination of factors present in your specific scenario.


Proprietary Bayesian analysis. 6-page personalized report. Full calculation transparency.

HIV Risk Calculator Resources

Learn more about how our Bayesian engine works, what factors influence HIV transmission probability and how to interpret your results.

Latest Risk Engine Update

The Bayesian model is regularly reviewed and refined as new evidence, methodology improvements and report functionality evolve.

VERSION 6.7
  • Evidence Audit of Risk Multipliers: All risk multipliers in the Bayesian framework were cross-referenced against the supporting peer-reviewed evidence used by the model.
  • Wound and Inflammation Adjustment: The applicable modifier was fine-tuned to better reflect published meta-analytic evidence.
  • Circumcision Factor Update: Circumcision logic was harmonized across relevant exposure pathways where the same biological mechanism applies.
  • On-Demand PrEP Calibration: The protection assumption for on-demand PrEP was adjusted to more closely reflect the IPERGAY evidence used by the model.
  • Multiple Partner Factor: The applicable partner-risk modifier was recalibrated against supporting epidemiological literature.
  • Intravenous Drug Use Logic: Partner-risk handling was reorganized within the formula to improve mathematical clarity and transparency.
  • Expanded Source Citations: Additional peer-reviewed sources were added directly to the report reference section.

View the full Risk Engine methodology and calculation logic