Temperature conversion chart
A formula card for temperature: Celsius, Fahrenheit and kelvin relate by addition, not multiplication. Formulas and printable examples.
Temperature is different from the other units on Skola: Celsius, Fahrenheit and kelvin do not relate by a simple multiplication – each scale has its own zero point. This formula card shows the relationships and printable examples.
Formulas
- Celsius to Fahrenheit°F = °C × 9/5 + 32
- Fahrenheit to Celsius°C = (°F - 32) × 5/9
- Celsius to kelvinK = °C + 273.15
- Kelvin to Celsius°C = K - 273.15
| °C | °F | K |
|---|---|---|
| -40 | -40 | 233.15 |
| 0 | 32 | 273.15 |
| 20 | 68 | 293.15 |
| 37 | 98.6 | 310.15 |
| 100 | 212 | 373.15 |
Minus 40 is the one point where Celsius and Fahrenheit agree: -40 °C = -40 °F. Both scales carry an offset, not just a ratio, so you cannot move the decimal point the way you can between metre and centimetre - each conversion needs the full formula.
Download PDFHow the card works
The formula card shows the four relationships between Celsius, Fahrenheit and kelvin, plus a small table of common values. Unlike the unit tables, the rows here are not editable – the formulas are fixed, because temperature cannot be written as a simple chain.
Print puts the card on a single portrait A4 and Download PDF gives you the same sheet as a file.
Why doesn’t a chain table work here?
The unit tables work by multiplying by a fixed factor: 1 m = 100 cm, 2 m = 200 cm, and so on. Temperature does not work that way. Each scale has its own zero point (Celsius zeroes at water’s freezing point, Fahrenheit at something else, kelvin at absolute zero) – the relationship is an addition, not just a multiplication.
Minus 40 is the odd one out: -40 °C is exactly -40 °F, the only temperature where the two scales agree. Check it in the formula: -40 × 9/5 + 32 = -72 + 32 = -40.
Roughly how warm?
- Water freezes at 0 °C (32 °F, 273.15 K).
- Room temperature is roughly 20 °C (68 °F).
- Normal body temperature is 37 °C (98.6 °F).
- Water boils at 100 °C (212 °F).
Frequently asked questions
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32: °F = °C × 9/5 + 32. 20 °C becomes 20 × 1.8 + 32 = 68 °F.
How do I convert Celsius to kelvin?
Add 273.15: K = °C + 273.15. 20 °C becomes 293.15 K.
Why isn’t temperature a chain table like the others?
The other units are pure ratios – double the value, double the result. The temperature scales have different zero points, so a single chain row would be wrong for every value except the one it was built for.
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