Temperature Converter – Celsius, Fahrenheit & Kelvin
Celsius, Fahrenheit, and Kelvin — formulas, steps, and charts
Formula & steps
°F = (°C × 9/5) + 32
°F = (°C × 9/5) + 32 °F = (25 × 9/5) + 32 °F = 45 + 32 °F = 77
Common values
Engineering examples
These values are common engineering examples (datasheet corners, room temperature, and high-temperature ratings). They are not a universal operating-temperature rating for every electronic component.
Natural-language input accepted: 25C, -40 F, 300K.
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Quick Answer
°F = (°C × 9/5) + 32. °C = (°F − 32) × 5/9. K = °C + 273.15. Water freezes at 0°C / 32°F / 273.15 K and boils at 100°C / 212°F / 373.15 K. The scales meet at −40°.
Temperature Converter
Convert Celsius, Fahrenheit, and Kelvin in both directions. Type a value — including negatives and decimals — and the other two scales update immediately.
°F = (°C × 9/5) + 32 · °C = (°F − 32) × 5/9 · K = °C + 273.15
Direction converters
- Celsius to Fahrenheit — locked °C → °F with a 0–100°C table
- Fahrenheit to Celsius — locked °F → °C
- Celsius to Kelvin
- Kelvin to Fahrenheit
- Kelvin to Celsius
- Fahrenheit to Kelvin
Formulas
| Direction | Formula |
|---|---|
| Celsius → Fahrenheit | °F = (°C × 9/5) + 32 |
| Fahrenheit → Celsius | °C = (°F − 32) × 5/9 |
| Celsius → Kelvin | K = °C + 273.15 |
| Kelvin → Celsius | °C = K − 273.15 |
| Fahrenheit → Kelvin | K = (°F + 459.67) × 5/9 |
| Kelvin → Fahrenheit | °F = (K × 9/5) − 459.67 |
Absolute zero is the lower bound: −273.15°C, −459.67°F, 0 K.
Absolute temperature vs temperature difference
10°C as a reading is 50°F. A rise of 10°C is 18°F, not 50°F. Use the Temperature Difference Calculator when you need ΔT.
Charts, formulas, and engineering tools
- Temperature Conversion Chart
- Celsius to Fahrenheit Formula
- Fahrenheit to Celsius Formula
- Thermistor Calculator
- Junction Temperature Calculator
Common numeric lookups
Design Notes
Electronics datasheets use Celsius exclusively. Standard operating ranges: commercial (0-70°C), industrial (-40 to 85°C), automotive (-40 to 125°C). Junction temperature is the most critical thermal parameter for IC reliability. Common corner values such as -55°C or 125°C are examples, not a universal rating for every part.
Common Mistakes
- 1
Forgetting the offset in Celsius-Fahrenheit conversion — it is NOT a simple multiplication.
- 2
Using ° symbol with Kelvin — correct notation is simply K, not °K.
- 3
Confusing temperature difference with absolute temperature — a 10°C rise = 18°F rise, but 10°C = 50°F.
Engineering Handbox
°F = (°C × 9/5) + 32 °F = (37 × 9/5) + 32 °F = 66.6 + 32 = 98.6
Knowledge Base
What is 0 Kelvin?
Absolute zero, the lowest possible temperature: 0 K = -273.15 °C = -459.67 °F. This converter will not calculate values below those limits.
How do I convert Celsius to Fahrenheit?
°F = (°C × 9/5) + 32. Example: 100°C = (100 × 1.8) + 32 = 212°F. Open the Celsius to Fahrenheit page for a locked-direction calculator and 0–100°C table.
How do I convert Fahrenheit to Celsius?
°C = (°F − 32) × 5/9. Example: 72°F = 22.2°C. Use the Fahrenheit to Celsius page when that is the only direction you need.
What is the relationship between Celsius and Kelvin?
K = °C + 273.15. The degree size is the same; only the zero points differ. Kelvin never uses the degree symbol (°).
At what temperature are Fahrenheit and Celsius equal?
At −40°. That is the unique crossover: −40°C = −40°F.
What temperature scale is used in electronics?
Datasheets use Celsius for operating ranges and junction temperatures. Common example ratings: commercial 0 to 70°C, industrial −40 to 85°C, automotive −40 to 125°C. Those bands are examples, not a universal part rating.
What is the difference between a temperature and a temperature difference?
Absolute conversion includes the 32 / 273.15 offsets. A difference does not: 1°C of rise = 1 K = 1.8°F. Use the Temperature Difference Calculator for ΔT.