Temperature Converter: Fahrenheit to Celsius Body Temperature, Oven 350°F to Celsius, Kelvin Absolute Zero
Convert between Celsius, Fahrenheit, Kelvin, Réaumur and Rankine using the correct offset formulas (not simple multipliers), so absolute and relative temperatures stay accurate. Type a value to update every scale instantly, swap source and target with one tap, copy a result, or compare all scales in the overview. Useful for weather, cooking, science and international travel.
Temperature conversion
Temperature Convert
All units overview
All Units Overview
How to Use
Temperature Converter Guide
Celsius / Fahrenheit / Kelvin / Réaumur / Rankine
The temperature converter supports precise conversion among five scales: Celsius (°C), Fahrenheit (°F), Kelvin (K), Réaumur (°Ré) and Rankine (°R). Unlike linear units such as length or weight, temperature involves absolute zero offsets, so there is no constant multiplier between scales — linear formulas with additions/subtractions must be used. The tool uses Kelvin as the internal base scale to ensure accuracy across all conversions, suitable for weather forecasting, cooking and baking, scientific experiments, industrial measurement and international travel.
01 The five scales
Celsius (°C) is the international standard, with water freezing at 0°C and boiling at 100°C at standard atmospheric pressure, widely used in China, Europe and most countries for daily life and science. Fahrenheit (°F) is mainly used in the US, with water freezing at 32°F and boiling at 212°F; the conversion is °F = °C × 9/5 + 32 and °C = (°F − 32) × 5/9.
Kelvin (K) is the thermodynamic (SI base) scale, with 0 K as absolute zero (the theoretical minimum, about −273.15°C); K = °C + 273.15, widely used in physics, chemistry and engineering. Réaumur (°Ré) was historically used in Europe, with freezing at 0° and boiling at 80°; °Ré = °C × 4/5. Rankine (°R) is the absolute Fahrenheit scale, with 0°R at absolute zero; °R = °F + 459.67 = K × 9/5, used in some engineering fields.
- °F = °C × 9/5 + 32
- K = °C + 273.15
- °Ré = °C × 4/5
- °R = (°C + 273.15) × 9/5 = K × 9/5
- Normal body temperature: 37°C = 98.6°F = 310.15 K
02 How to use
Enter a temperature and choose the source scale on the left; the right instantly shows the target, and the all-units overview lists all five scales. Temperature has no "conversion rate," so the tip bar notes that temperature uses absolute-offset conversion. Common scenarios: checking a foreign weather forecast (°C ↔ °F), oven temperature conversion (°C ↔ °F), and scientific data processing (°C ↔ K).
Inputs and actions
- value fieldEnter the temperature to convert; results update instantly.
- scale buttonsTap a scale (°C/°F/K/°Ré/°R) to set source or target.
- ⇄ SwapReverses the source and target scales in one click.
- CopyCopies the full "X = Y" result to the clipboard.
- ResetRestores the default source/target scales and value.
Output
- target resultThe converted temperature in the selected scale (read-only).
- offset noteReminds you that temperature uses linear offset formulas, not a ratio.
- all unitsLists the value in all five scales at once; source is green, target blue.
- Temperature has no constant ratio — use linear formulas with offsets
- Absolute zero is 0 K = −273.15°C = −459.67°F
- Celsius and Fahrenheit are most common in daily life; Kelvin is mainly for science
- Oven conversion: 180°C ≈ 356°F (often rounded to 350°F)
FinCompute’s free online temperature converter supports Celsius (°C), Fahrenheit (°F), Kelvin (K), Réaumur (°Ré) and Rankine (°R). Whether you need Fahrenheit to Celsius for a fever check, oven 350°F to Celsius for baking, or Kelvin absolute zero for a science problem, real offset formulas (not simple multipliers) keep every conversion accurate.
Celsius and Fahrenheit: body temperature, oven and weather conversion
Celsius (°C) freezes water at 0° and boils at 100° at standard atmospheric pressure, used worldwide for weather, science and daily life. Fahrenheit (°F) freezes at 32° and boils at 212°, mainly used in the United States for weather and cooking. °F = °C × 9/5 + 32; °C = (°F − 32) × 5/9. Convert 100°F fever, 37°C body temperature and 350°F oven in one input.
Kelvin: thermodynamic scale and absolute zero conversion
Kelvin (K) has 0 K at absolute zero (−273.15°C), the theoretical point where molecular motion stops. K = °C + 273.15. Kelvin is the SI base unit for temperature and is used in all scientific and engineering calculations — gas laws, thermodynamics, material science and climate models. "What is absolute zero in Celsius/Fahrenheit" is a common query.
Réaumur and Rankine: historical and engineering scales
Réaumur (°Ré) freezes at 0° and boils at 80° (°Ré = °C × 4/5), historically used in parts of Europe for cheese-making and food processing. Rankine (°R) is the absolute Fahrenheit scale (°R = °F + 459.67 = K × 9/5), still used in some US engineering thermodynamics references.
Common temperature conversions: fever, oven, room temperature and science
Travelers convert weather forecasts between °C and °F; cooks convert oven temperatures (e.g., 180°C ≈ 350°F or "moderate oven"); HVAC technicians compare setpoints; medical professionals note that normal body temperature is about 37°C = 98.6°F and 100°F ≈ 37.8°C is near fever; scientists convert to Kelvin for gas laws and thermodynamics.
Temperature formulas and ITS-90: real offsets, not simple multipliers
Celsius to Fahrenheit: °F = °C × 9/5 + 32. Fahrenheit to Celsius: °C = (°F − 32) × 5/9. Celsius to Kelvin: K = °C + 273.15. Fahrenheit to Kelvin: K = (°F + 459.67) × 5/9. Modern temperature scales are defined by the International Temperature Scale of 1990 (ITS-90), maintained by BIPM; our converter chains all scales through Kelvin internally.
Last updated: 2026-08-23
FAQ
QWhy can’t temperature use a simple multiplier?
Because Celsius and Fahrenheit have different zero points (0°C = 32°F), not just different degrees sizes. A formula with an offset (°F = °C × 9/5 + 32) is required. Multiplying alone would give 0°F = 0°C, which is wrong.
QWhat is normal body temperature?
About 37°C = 98.6°F = 310.15 K. Normal ranges vary from 36.1–37.2°C (97–99°F); a fever is generally considered 38°C (100.4°F) or above.
QWhat is absolute zero?
0 K = −273.15°C = −459.67°F, the theoretical minimum temperature at which thermal energy is at its minimum. It has never been reached experimentally.
QWhat is 180°C in Fahrenheit?
180°C × 9/5 + 32 = 356°F, usually rounded to 350°F in oven recipes. This is considered a "moderate" oven temperature.
QCan Kelvin be negative?
No. Kelvin starts at absolute zero (0 K), so negative Kelvin temperatures do not exist on the thermodynamic scale. (Negative absolute temperatures can be defined in specialized quantum systems but are not "cold" in the everyday sense.)
QWhat is a comfortable room temperature?
Generally 20–22°C (68–72°F). The WHO recommends at least 18°C (64.4°F) for healthy adults, and warmer for children, the elderly or those in poor health.
QWhy do Americans still use Fahrenheit?
Fahrenheit was adopted early in the US and became embedded in manufacturing, weather reporting and daily life. Congress legalized metric in 1866 but never mandated conversion, so Fahrenheit remains the standard for weather and cooking.
QWhat is 350 °F in Celsius for baking?
350 °F ≈ 176.7 °C, usually rounded to 180 °C in oven recipes, considered a "moderate" oven. Use the temperature converter to switch any recipe between °F and °C instantly.
QIs 100 °F a fever? What is it in Celsius?
100 °F ≈ 37.8 °C. A fever is generally considered 38 °C (100.4 °F) or above; normal body temperature is about 37 °C / 98.6 °F. Enter the value to see °C, K, Réaumur and Rankine together.
QWhat is 37 °C in Fahrenheit and Kelvin?
37 °C = 98.6 °F = 310.15 K. The converter shows all five scales — Celsius, Fahrenheit, Kelvin, Réaumur and Rankine — from a single input.
QWhat temperature is absolute zero?
Absolute zero is 0 K = −273.15 °C = −459.67 °F = 0 °R, the theoretical minimum temperature where thermal energy is at its minimum. It has never been reached experimentally.
QWhat is 200 °C in Fahrenheit for baking?
200 °C × 9/5 + 32 = 392 °F, usually rounded to 400 °F in US oven recipes — considered a "moderately hot" oven. A typical 180 °C recipe is 350 °F (moderate).
QWhat is 98.6 °F in Celsius?
98.6 °F ≈ 37 °C (36.98), the textbook normal human body temperature established in the 19th century. Modern studies put the average closer to 36.4–36.7 °C; a fever is generally 38 °C (100.4 °F) or higher.