Your result will appear here
Fill in the fields and press Calculate.
Celsius and Fahrenheit are two temperature scales with different zero points and different degree sizes, so converting isn't a simple multiplication — there's an offset too. This tool applies the formula for you, turning Celsius into Fahrenheit and back.
Celsius to Fahrenheit Converter: step-by-step worked example
What is a 38.5 °C fever in Fahrenheit?
- Value
- 38.5
- Direction
- Celsius → Fahrenheit
- 1
Scale factor
Water freezes at 0 °C / 32 °F and boils at 100 °C / 212 °F → 180 ÷ 100 = 9/5
(212 − 32) ÷ (100 − 0) = 1.8 = 1.8
- 2
First operation
°C → °F: °C × 9/5 · °F → °C: °F − 32
38.5 × 9 ÷ 5 = 69.3
- 3
Result
°F = °C × 9/5 + 32 · °C = (°F − 32) × 5/9
69.3 + 32 = 101.3 °F
- 4
Check (reverse direction)
Convert the result back with the other formula
(101.3 − 32) × 5 ÷ 9 = 38.5 °C
- Below freezing
- Cold–cool
- Mild–warm
- Body temp.
- Fever
- Below boiling
- Above boiling
- Water freezes (0 °C)32 °F
- Room (20 °C)68 °F
- Body (37 °C)98.6 °F
- This example101.3 °F
- Water boils (100 °C)212 °F
Good to know: Quick estimate: °C × 2 + 30 ≈ °F (a few degrees off at everyday temperatures). −40 is the same in both scales; normal body temperature is 37 °C = 98.6 °F.
Celsius to Fahrenheit Converter — how it works
The conversion factor
Unlike most conversions, temperature has both a scale factor and an offset:
| Direction | Formula |
|---|---|
| °C → °F | (°C × 9/5) + 32 |
| °F → °C | (°F − 32) × 5/9 |
The scales cross at −40°, where °C and °F read the same.
Common values
| Celsius | Fahrenheit |
|---|---|
| 0 °C | 32 °F |
| 20 °C | 68 °F |
| 37 °C | 98.6 °F |
| 100 °C | 212 °F |
Worked example
Body temperature of 37 °C is (37 × 9/5) + 32 = 98.6 °F. A 72 °F room is (72 − 32) × 5/9 = 22.2 °C. Water freezes at 0 °C / 32 °F and boils at 100 °C / 212 °F.
Celsius to Fahrenheit table
| °C | °F |
|---|---|
| -40 | -40 |
| -20 | -4 |
| -10 | 14 |
| 0 | 32 |
| 5 | 41 |
| 10 | 50 |
| 15 | 59 |
| 20 | 68 |
| 25 | 77 |
| 30 | 86 |
| 35 | 95 |
| 36.6 | 97.9 |
| 37 | 98.6 |
| 38 | 100.4 |
| 39 | 102.2 |
| 40 | 104 |
| 50 | 122 |
| 100 | 212 |
Fahrenheit to Celsius table
| °F | °C |
|---|---|
| 0 | -17.8 |
| 32 | 0 |
| 50 | 10 |
| 68 | 20 |
| 77 | 25 |
| 86 | 30 |
| 98.6 | 37 |
| 100 | 37.8 |
| 104 | 40 |
| 212 | 100 |
Frequently asked questions
How do I convert Celsius to Fahrenheit?+
Multiply by 9/5 (i.e. 1.8) and add 32. So 25 °C = 25 × 1.8 + 32 = 77 °F. A quick estimate is “double and add 30”.
How do I convert Fahrenheit to Celsius?+
Subtract 32, then multiply by 5/9. For example, 100 °F = (100 − 32) × 5/9 = 37.8 °C.
Why isn't it a simple multiplication?+
Because the two scales have different zero points — 0 °C is 32 °F — so you need an offset of 32 as well as the 9/5 scale factor. That's why the formula has both a multiply and an add.
At what temperature are Celsius and Fahrenheit equal?+
At −40°. Minus 40 degrees Celsius is exactly minus 40 degrees Fahrenheit — the one point where the two scales meet.
What is a normal body temperature in Fahrenheit?+
The classic figure is 98.6 °F, which is 37 °C. Normal readings actually range a little either side of that.
About this page
- Publisher:
- Kalkoro — Teknolojig Bilişim Teknolojileri A.Ş., İstanbul
- Written by:
- Ahmet Tur — Editor (Math, date & time, unit conversion, physics & chemistry, everyday tools)
- Reviewed by:
- Kübra Yıldız — Editor
Parameters come from official sources; the last update date is shown at the bottom of the page.
Spotted a wrong result? Use the "Report a bug" button at the top of the page; every report is reviewed.
How we calculate and our accuracy policy →
Results are for information only. For official matters the relevant authority's calculation prevails.
Last updated: