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Fever Checker

Toolsda's Fever Checker places a temperature reading on the WHO & CDC body temperature chart — normal is roughly 36.1–37.2°C (97–99°F), a high fever is generally 39.5°C (103°F) or above. Works for adults and children, oral, armpit or ear readings. Nothing you enter leaves your browser.

Your reading

For informational purposes only — not medical advice. Consult a healthcare professional.

Armpit readings are adjusted +0.5°C to estimate an oral-equivalent temperature before checking the chart.

Your result

37°C
=
98.6°F
Normal

Within the typical adult body temperature range.

37 °C
Your Value
37 °C
Category
Normal
Range
36.1 - 37.2°C

When to see a doctor

  • Fever above 39.4°C (103°F) in an adult, or above 38°C in an infant under 3 months
  • Fever lasting more than 2-3 days, or that keeps returning
  • Fever with a stiff neck, rash, severe headache, difficulty breathing, or confusion
  • Fever in someone with a weakened immune system or chronic illness
  • Any fever you're unsure about in a young child — when in doubt, call a pediatrician

How to measure correctly

  • Wait 15-20 minutes after eating, drinking, or exercising
  • Oral readings: place under the tongue, lips closed
  • Armpit readings run ~0.5°C lower than oral — this tool adjusts for that
  • Ear (tympanic) readings should be pointed straight down the ear canal
  • Rest for a few minutes before taking a child's temperature
  • Take 2 readings a few minutes apart if the first seems unusual

Frequently Asked Questions

What is a normal body temperature?

A typical adult oral temperature is around 36.1-37.2°C (97-99°F). Normal temperature varies slightly by person, time of day, and measurement site.

Is 37.5°C a fever?

37.5°C is at the upper edge of the typical range and may be classified as a low-grade fever depending on the measurement site and individual baseline. Rest, hydrate, and monitor.

What temperature counts as a high fever?

Generally, 39.5°C (103°F) or above is considered a high fever in adults. Temperatures of 40°C (104°F) or above call for prompt medical attention.