HerpesChance is a free, evidence-based platform that helps people understand their statistical risk of carrying common sexually transmitted infections. We build machine-learning models on publicly available CDC data and translate them into accessible, interactive calculators that anyone can use in seconds.
The site was created because most STI risk information online is either too vague ("it's common") or too clinical to be useful. We wanted to give people a concrete, personalized estimate they could take to a conversation with their doctor — not a diagnosis, but a starting point.
Seven individual calculators, each trained on NHANES serology data from the CDC:
Each calculator provides a probability estimate displayed as a gauge chart, along with percentile rankings and population-level comparisons. The Full Panel runs all seven calculators from a single form.
The Learn section contains articles on HSV testing, prevalence statistics, transmission, and the differences between HSV-1 and HSV-2. Articles are written and reviewed for clarity and alignment with CDC and WHO guidance.
Each calculator uses a machine-learning model (logistic regression or gradient boosting) trained on data from the CDC National Health and Nutrition Examination Survey (2005–2016). NHANES combines interviews, physical exams, and laboratory blood tests on a nationally representative sample of the US population. Our models learn the statistical relationships between demographic, lifestyle, and behavioral variables and serological test results, then apply those relationships to your inputs to produce a probability estimate.
For full technical details — feature selection, training procedures, hyperparameters, calibration, validation metrics, and limitations — see the Methodology page.
All training data comes from publicly available, de-identified NHANES datasets. No personally identifiable information is used in model development.
When you use a calculator, your inputs are processed on the server to generate a result and are not stored in any database or user profile. No account creation is required. For details on cookies, analytics, and advertising partners, see our Privacy Policy.
These calculators are educational tools, not diagnostic tests. They estimate the statistical probability of seropositivity based on population-level patterns. They cannot confirm or deny whether you have an infection. Only laboratory testing can do that.
No medical action should be taken based solely on a calculator result. If you are concerned about an STI, consult a licensed healthcare provider for proper testing and guidance.
While we have worked to make these models as accurate as possible, they rely on a limited number of inputs and cannot capture the full complexity of individual risk. Results are estimates, not certainties. See our full Medical Disclaimer for more.
HerpesChance was created by Mark Sanborn, PhD, a biomedical researcher with expertise in bioinformatics, genomics, and statistical modeling. Content is written and reviewed for accuracy and alignment with reputable public-health sources.
HerpesChance is free for everyone and always will be. Running the servers, maintaining the models, and writing new content takes time and money. If you found this site helpful, consider supporting it.
Questions, corrections, or feedback: herpeschance@gmail.com