Know Your Real Chances

If you're wondering "what are my chances of having herpes?" — you're not alone. HerpesChance is the only site that calculates your individual probability of carrying common sexually transmitted infections and gives you an estimated percent. Each calculator uses a machine-learning model trained on data from the CDC National Health and Nutrition Examination Survey (NHANES), covering six survey cycles from 2005 to 2016.

Herpes simplex virus type 1 (HSV-1) causes oral herpes and is carried by roughly 48% of US adults — so the chances of having herpes are higher than most people think. HSV-2 is the leading cause of genital herpes, affecting about 12%. Because many carriers never show symptoms, most people don't know their status without testing. Our herpes risk calculator helps you find out your risk based on your demographics and lifestyle.

Beyond herpes, we also cover Hepatitis B (5.4% ever-exposed), Hepatitis C (1.5%, with injection drug use as the dominant risk factor), and three HPV types including the high-risk strains linked to cervical cancer.

These tools are educational, not diagnostic. They estimate your herpes probability and STD risk based on population-level patterns — they cannot confirm or deny infection. If you have concerns, consult a licensed healthcare provider for proper testing. See our Methodology for full technical details.