Temperature Converter
Convert between Celsius, Fahrenheit and Kelvin instantly — with the exact formulas and key reference points.
Reference points: water freezes at 0 °C / 32 °F / 273.15 K and boils at 100 °C / 212 °F / 373.15 K; body temperature is 37 °C / 98.6 °F; −40 °C equals −40 °F (the scales cross there). Kelvin has no negative values — 0 K is absolute zero, the coldest possible temperature.
Formula
About Temperature Converter
The temperature converter handles the conversion everyone needs when reading foreign weather, following recipes, or doing science homework: Celsius, Fahrenheit and Kelvin, all at once. Enter a temperature in any scale and it shows the other two instantly, using the exact conversion formulas. It covers the everyday cases (is 30 °C hot? what's 350 °F in Celsius for the oven?) and the scientific one (Kelvin for absolute temperature), with the key reference points — freezing, boiling, body temperature, and the famous −40° where Celsius and Fahrenheit meet — to anchor your intuition.
How to use Temperature Converter
- 1Enter your values into Temperature Converter — sensible, domain-typical defaults are pre-filled so you see a real result immediately.
- 2The result recomputes live using the formula shown on the page; there is no button to press.
- 3Adjust any input to compare scenarios, then read the worked example to see the substituted numbers.
Why use Temperature Converter?
- ✓Computes Temperature Converter instantly in your browser — no sign-up, no upload, no server round-trip.
- ✓100% free and unlimited, with the exact formula shown: °F = °C × 9/5 + 32.
- ✓Runs entirely client-side, so every value you enter stays private on your device.
- ✓Live recompute as you type, with a worked example and authoritative references for trust.
Frequently asked questions
How do I convert Celsius to Fahrenheit?+
Multiply by 9/5 (1.8) and add 32: °F = °C × 1.8 + 32. So 20 °C = 68 °F, 30 °C = 86 °F, 100 °C = 212 °F. A quick mental shortcut: double the Celsius and add 30 for a rough estimate (20 → 70, close to the exact 68). To go back, subtract 32 then divide by 1.8.
What is Kelvin and why use it?+
Kelvin is the absolute temperature scale used in science: it starts at absolute zero (0 K = −273.15 °C), the coldest possible temperature where molecular motion stops, and has no negative values. A degree change in Kelvin equals one in Celsius (K = °C + 273.15). It's essential for gas laws, thermodynamics and any physics where ratios of temperature matter.
At what temperature do Celsius and Fahrenheit read the same?+
−40°. It's the only point where the two scales cross: −40 °C = −40 °F. This falls out of the formulas — set °C = °F = x and solve x = 1.8x + 32. It's a handy fact for remembering the conversion direction and a memorable quirk of the two scales.
What are the key temperatures to remember?+
Water freezes at 0 °C / 32 °F and boils at 100 °C / 212 °F (at sea level); normal body temperature is 37 °C / 98.6 °F; a comfortable room is ~21 °C / 70 °F; and a hot summer day of 35 °C is 95 °F. Anchoring to these makes unfamiliar temperatures in the other scale instantly meaningful.
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