Herpes Risk Calculators

Choose a calculator below to estimate your risk

HSV-1 — Oral Herpes

HSV-1 is the most common herpes type, carried by roughly half of US adults. It primarily causes cold sores but can also cause genital infections through oral contact. Most people acquire it in childhood and many never show symptoms.

  • 16 demographic & lifestyle factors
  • Trained on NHANES 2005-2016 (~44,000 participants)
  • Includes gauge, percentile, and comparison charts
HSV-1 Calculator

HSV-2 — Genital Herpes

HSV-2 is the leading cause of genital herpes, affecting about 12% of US adults aged 14-49. Many carriers are unaware of their infection because symptoms can be mild or absent. Transmission can occur even without visible sores.

  • 20 demographic, lifestyle & behavioral factors
  • Trained on NHANES 2005-2016 (~44,000 participants)
  • Includes gauge, percentile, and comparison charts
HSV-2 Calculator

What's the difference? HSV-1 and HSV-2 are closely related viruses that both cause lifelong infection. The key differences:

  • Location: HSV-1 typically infects orally (cold sores), HSV-2 typically infects genitally — though either type can appear at either site.
  • Prevalence: HSV-1 is far more common (~48% of US adults) than HSV-2 (~12%).
  • Recurrence: Genital HSV-2 recurs more frequently than genital HSV-1. Oral HSV-1 recurs more often than oral HSV-2.
  • Testing: Type-specific IgG blood tests can distinguish between HSV-1 and HSV-2 antibodies.

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How Common Is Herpes?

Herpes is far more common than most people realize. According to the CDC, approximately 48% of Americans aged 14–49 carry HSV-1 (oral herpes), and about 12% carry HSV-2 (genital herpes). Worldwide, the WHO estimates that 3.7 billion people under 50 have HSV-1 and 491 million people aged 15–49 have HSV-2.

Because most herpes carriers never develop noticeable symptoms, the majority of people with herpes don't know they have it. The CDC estimates that about 87% of people with HSV-2 have never received a clinical diagnosis. This means the chances of having herpes — particularly HSV-1 — are higher than most people expect.

Risk factors vary by type. HSV-1 is often acquired in childhood through non-sexual contact like kissing, while HSV-2 is primarily transmitted through sexual contact. Your risk of getting herpes depends on factors like age, number of sexual partners, race/ethnicity, and geographic location. Our calculators above estimate your individual probability based on these factors.

Frequently Asked Questions

What are my chances of having herpes?

Your chances depend on your age, sex, race, sexual history, and other demographic factors. In the US, roughly 1 in 2 adults have oral herpes (HSV-1) and about 1 in 8 have genital herpes (HSV-2). Use our HSV-1 calculator or HSV-2 calculator to get a personalized estimate based on your profile.

Can you have herpes and not know it?

Yes. Most people with herpes have no symptoms or very mild symptoms they don't recognize. The CDC estimates that about 87% of people with HSV-2 have never been clinically diagnosed. Many people with HSV-1 are also unaware of their infection, especially if they were infected in childhood and never had a noticeable cold sore.

How is herpes diagnosed?

Herpes can be diagnosed through type-specific IgG blood tests (which detect antibodies to HSV-1 or HSV-2) or through PCR swab tests of active sores. Blood tests can identify past infection even without symptoms. IgM tests are generally not recommended because they cannot reliably distinguish between HSV-1 and HSV-2.

Should I get tested for herpes?

The CDC does not recommend routine herpes screening for people without symptoms. However, testing may be appropriate if you have symptoms, a partner with known herpes, are pregnant, or simply want to know your status. Talk to a healthcare provider about whether testing makes sense for your situation.

Medically reviewed by Mark Sanborn, PhD — Biomedical researcher specializing in bioinformatics, genomics, and statistical modeling. Last reviewed March 2026. See methodology · Medical disclaimer