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Free health tool

Celsius to Fahrenheit converter

Convert an existing temperature value between °C and °F without classifying it or giving medical advice.

  • Free
  • Instant result
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Calculate your result

Enter one recorded value without a unit or thousands separator. Use a full stop when a comma with three following digits could be ambiguous.

Accepted range: -273.15 to 1000 °C

Your result will appear here

Nothing is saved or added to the URL.

What this result means

Choose the unit you have and enter one temperature value. The converter uses °F = °C × 1.8 + 32 and the exact inverse. It changes the unit only and does not interpret the reading. [1][2]

What °C and °F mean

Celsius and Fahrenheit are two temperature scales. A Celsius degree interval corresponds to 1.8 Fahrenheit degrees, and the scales have different zero points. [1][2]

Why the conversion adds 32

The scales align at −40°, but 0 °C equals 32 °F. That offset gives °F = °C × 1.8 + 32 and the inverse °C = (°F − 32) ÷ 1.8. [1][2]

The scales meet at −40°

At −40, both scales show the same number. This is a useful arithmetic check, not a statement about safe exposure or health. [1]

Why displays may differ slightly

A device or record may already round its value. This tool calculates from what you enter and rounds the converted display to two decimals. [1]

What this conversion cannot tell you

Changing the unit cannot determine whether a body, room, weather, appliance or other temperature is expected, safe or accurately measured.

Formula and assumptions

Formula
°F = °C × 1.8 + 32. °C = (°F − 32) ÷ 1.8. [1][2]
Version
Celsius and Fahrenheit temperature conversion, nist-celsius-fahrenheit-v1
Rounding
Use the exact temperature-scale equations and round once for display to two decimal places.
Worked example
For 37 °C: 37 × 1.8 + 32 = 98.6 °F. For 98.6 °F: (98.6 − 32) ÷ 1.8 = 37 °C. [1][2]

Who this is for — and when not to use it

Intended use

Neutral unit conversion of one existing temperature value from a thermometer, wearable, weather, room or other record.

Not intended for

This tool does not decide whether a body temperature is normal, a fever or an emergency, assess symptoms, validate a device, recommend treatment, or provide food-safety guidance.

Exclusions

  • Fever or hypothermia classification
  • Diagnosis, symptom assessment or emergency triage
  • Treatment or medication decisions
  • Thermometer calibration or measurement-site correction
  • Cooking or food-safety decisions

Evidence sources

  1. 1. SI Units — Temperature — National Institute of Standards and Technology. Accessed Aug 9, 2026.
  2. 2. NIST Guide to the SI, Appendix B.8: Factors for Units Listed Alphabetically — National Institute of Standards and Technology. Accessed Aug 9, 2026.