Body Temperature Reference
Is a temperature normal, low or feverish? Bands by measurement site, with the modern-average update.
The famous 98.6°F is a 170-year-old average that modern data has nudged down to ~97.9°F — and everyone cycles ~0.5°C through the day (lowest at dawn, highest in the evening). Measurement site matters: armpit reads ~0.5°C below core, ear and forehead vary. The number is far less important than how the person feels and accompanying signs — and any fever in an under-3-month infant is an immediate medical matter.
Formula
For general information only — not medical advice, a diagnosis or a treatment plan. Consult a qualified healthcare professional before making health, diet, medication or exercise decisions.
Is a temperature normal, low or feverish? Bands by measurement site, with the modern-average update. The Body Temperature Reference is a free, private normal body temperature tool — every result computes instantly in your browser with no sign-up and no data upload.
About Body Temperature Reference
The famous 98.6°F is a 170-year-old average that modern data has nudged down to ~97.9°F — and everyone cycles ~0.5°C through the day (lowest at dawn, highest in the evening). It applies fever ≈ ≥38.0°C / 100.4°F; the '98.6°F average' is outdated (now ~97.9°F). Use the Body Temperature Reference to get an instant, clearly-explained result with the working shown step by step — free, private and with the source method cited.
How to use Body Temperature Reference
- 1Enter your details in the Body Temperature Reference input fields above.
- 2The result updates instantly with the working and reference bands shown.
- 3Adjust any value to explore how it changes the outcome — it's free and unlimited.
Why use Body Temperature Reference?
- ✓Instant normal body temperature result that recomputes as you type — no waiting, no page reloads
- ✓100% client-side: your health data never leaves your browser
- ✓Shows the actual formula and your numbers substituted in, so you can see exactly how the result is reached
- ✓Based on published, citable sources (Protsiv M et al., eLife 2020 — declining human body temperature)
- ✓Free forever with no sign-up, account or app install
Frequently asked questions
How does the Body Temperature Reference work?+
The famous 98.6°F is a 170-year-old average that modern data has nudged down to ~97.9°F — and everyone cycles ~0.5°C through the day (lowest at dawn, highest in the evening). The calculation uses the formula: fever ≈ ≥38.0°C / 100.4°F; the '98.6°F average' is outdated (now ~97.9°F). Everything runs instantly in your browser as you type — your inputs are never uploaded.
Is the Body Temperature Reference accurate, and what is it based on?+
The method is traceable to authoritative sources: Protsiv M et al., eLife 2020 — declining human body temperature. Results are estimates — individual variation always applies, so treat the output as a well-grounded starting point.
Is the Body Temperature Reference free and private?+
Yes. It's completely free with no sign-up, and all computation happens locally in your browser, so none of your health data ever leaves your device.
Can I use this for medical decisions?+
This tool is for general information only and is not medical advice. Always consult a qualified healthcare professional before making health decisions.
What can I use the Body Temperature Reference for?+
It's commonly used for normal body temperature, fever temperature chart, 98.6 normal. Is a temperature normal, low or feverish?
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