HIV RISK CALCULATOR

CONFIDENTIAL ONLINE ASSESSMENT

RISK_ENGINE_v6.0 - SYSTEM ONLINE

The most sophisticated HIV risk calculator on the web

CALCULATE YOUR HIV RISK USING OUR PROPRIETARY, AI-POWERED ANALYSIS TOOL.

Built to give peace of mind and replace panic with probability.

Built on data from CDC, WHO, and NHS.
START YOUR REPORT

How It Works

  1. Answer Questions: Confidentially answer questions about your specific encounter.

  2. AI Analysis: Our engine cross-references your inputs against a matrix of verified epidemiological data.

  3. Receive Report: Get an immediate, encrypted report with your calculated risk probability and clear next steps.

Why Trust The Results

  • Algorithms verified against peer-reviewed epidemiological studies.
  • Full transparency into our calculation logic.
  • A powerful, data-driven tool for informed decisions.

FROM THE KNOWLEDGE BASE

Have a question about testing or transmission? Check out our blog for answers to commonly asked questions.

VISIT THE BLOG

Version Updates

Our risk engine is constantly being refined based on the latest data. See a full breakdown of our methodology and data sources.

VERSION 6.0
  • Major Update: Integrated PrEP (Pre-Exposure Prophylaxis) logic into the risk calculation.
  • The model now accounts for user adherence with specific pathways for perfect daily use, on-demand dosing (2-1-1), missed doses, and recent initiation.
  • Each adherence level is mapped to a clinically-backed risk reduction multiplier (e.g., up to 99% for perfect use).
  • The tool now provides enhanced decision support, recommending users with compromised PrEP protection consider PEP.
VERSION 5.6
  • Patched linguistic ambiguity in the risk modifier output.
VERSION 5.5
  • Enhanced tissue integrity modeling for transmission probability.
  • Corrected HIV prevalence data streams for MSM vs. general population.
VERSION 5.4
  • Implemented an ART logic override: The template now automatically uses the more realistic 'Don't Know' ART calculation if the partner's overall HIV status is 'Don't Know', even if 'No' was selected for the ART question.
  • Updated circumcision logic: The upward risk multiplier for being uncircumcised now only applies if a condom was not used.
VERSION 5.3
  • The protective benefit of "no ejaculation" is now correctly applied only to receptive partners whereas before it was a change based on manual QA.
VERSION 5.2
  • Report now includes a “Comparison to Other STIs” section showing relative likelihoods vs. HIV.
VERSION 5.1
  • Added test timing calculator based on user’s exposure date.
  • Shows personalised lab & oral test dates to avoid false negatives.
VERSION 5.0
  • ART coverage logic improved — now factors in three country-level stats (diagnosis rate, treatment access, and viral suppression), giving a more realistic picture of how many people are actually suppressed. This helps account for undiagnosed cases and better reflects real-world transmission odds.
  • Sex worker risk logic revised — adjusted to be more conservative, while still accounting for higher exposure rates due to occupational partner turnover.
  • Multiple partners logic refined — risk estimates now better reflect the increased exposure likelihood when a partner has had 2+ partners in the past 6 months.
VERSION 4.9
  • ART coverage now splits by population: MSM vs general public.
  • Improves accuracy by reflecting real-world disparities in ART access for MSM.
VERSION 4.8
  • Expanded risk pathway logic to account for instances where the user is not circumcised.
VERSION 4.6 & 4.7
  • Wound and inflammation risk now included, increasing transmission estimates if the user had open cuts, sores, or irritation during sex (only applied when no condom was used).
  • Step Two now clearly explains how wound-based risk affects your overall probability, using plain language.
  • Full breakdown of probability logic includes better explanation of how the partner’s HIV estimate and act-specific transmission risk combine to calculate final odds.
VERSION 4.5
  • PEP guidance now adapts to risk tier, clarifying when it’s typically not recommended but still available for high-anxiety or anal sex cases.
  • New “What If It Was Anal?” FAQ added for users who select “multiple sex types” without specifying the act.
  • “What We Recommend” section rewritten for sharper tone, emotional clarity, and faster readability.
VERSION 4.4
  • Real-world ART logic now applies regional treatment coverage rates when ART status is unknown.
  • Expanded risk pathway logic to include role-specific (insertive vs receptive) modifiers.
  • MSM-specific prevalence now replaces general population prevalence for male-male encounters.
VERSION 4.0
  • Introduced emotional reinforcement and alternate scenarios to reduce panic.
  • Added personalised risk recommendations based on calculated probability.
  • Cleaned up visual flow for mobile-first readability.
VERSION 3.0
  • Transitioned to per-act risk modelling using fraction and percentage logic.
  • Integrated global gender-stratified HIV prevalence estimates.
  • Upgraded condom effectiveness to reflect real-world meta-analytic data.
  • Introduced transparent breakdown of all conditional inputs in Step Three.