Temperature Converter Calculator for Everyday Use
Type once and every scale updates instantly. Quick entry, presets, and 0–6 decimals cover cooking, travel, and homework.
Free · Instant · Client-side
Free Temperature Converter
Convert °C, °F, K, and more - instantly.
All major scales, one panel
Edit any unit and every other scale updates instantly. Celsius, Fahrenheit, Kelvin, Rankine, and Réaumur - with presets, precision control, and shareable links.
What Is a Temperature Converter?
A temperature converter is an online tool that translates a reading from one temperature scale into another. Whether you are checking weather, following a recipe, or reading a science textbook, you often need the same physical temperature in Celsius, Fahrenheit, Kelvin, or another unit. A reliable temperature converter calculator returns accurate results in seconds without manual formulas.
Unlike a static chart, a modern temperature converter updates every scale at once as you type. Start from degrees Celsius, Fahrenheit, kelvin, rankine, or réaumur and immediately see equivalent values everywhere else. Our tool runs entirely in your browser, so conversions stay private and work after the first page load.
Celsius to Fahrenheit and F to C Conversions
°F = (°C × 9/5) + 32. Swap °C and °F in one click, or convert from kelvin, rankine, and réaumur in the same panel.
Kelvin, Rankine, Réaumur, and Fahrenheit Output
All five scales in one view. Conversions run through kelvin internally so results stay precise and consistent.
How to Use This Free Temperature Converter
Edit any field, share a link, copy a result, or choose your unit from the dropdown. No account required - works offline after the first load.
Frequently asked questions
What is the formula for a temperature converter?
Celsius to Fahrenheit: °F = (°C × 9/5) + 32. Fahrenheit to Celsius: °C = (°F - 32) × 5/9. Kelvin: K = °C + 273.15. Rankine: °R = °F + 459.67. A temperature converter applies these formulas automatically so you do not have to calculate by hand.
How do you convert Celsius to Fahrenheit?
Multiply the Celsius value by nine-fifths (or 1.8), then add 32. Example: 25 °C × 9/5 + 32 = 77 °F. Water freezes at 0 °C (32 °F) and boils at 100 °C (212 °F). Enter any Celsius value in our converter to see Fahrenheit instantly.
How do you convert F to C easily?
Subtract 32 from Fahrenheit, then multiply by five-ninths (or 0.555…). Example: 68 °F → (68 - 32) × 5/9 = 20 °C. For a rough mental estimate near room temperature, subtract 30 and halve the result - then use our converter when you need an exact answer.
How to calculate C to F easily?
Exact method: multiply °C by 1.8 and add 32. Quick estimate: double the Celsius value and add 30 (e.g. 20 °C → about 70 °F; exact 68 °F). For cooking, weather, or science, type the Celsius reading into our temperature converter for a precise Fahrenheit result.
How to quickly go from C to F?
The fastest way is to use an online temperature converter - enter Celsius and read Fahrenheit immediately. Mental shortcut: °C × 2 + 30 gives a ballpark for everyday temperatures. For accuracy, use °F = (°C × 9/5) + 32 or our tool with one click.
Can I convert C to F in my head?
Yes, approximately. Double the Celsius temperature and add 30 for a rough Fahrenheit estimate (works well between 0 °C and 30 °C). Example: 10 °C → about 50 °F (exact 50 °F). For body temperature, oven settings, or lab work, use the exact formula or our converter.
What are the 4 units of temperature?
The four most widely used scales are Celsius (°C), Fahrenheit (°F), Kelvin (K), and Rankine (°R). Celsius and Fahrenheit are everyday scales; Kelvin and Rankine are absolute scales starting at absolute zero. Our converter also supports Réaumur (°Ré), a fifth historical scale.
Is 1 °F equal to 1 °C?
No. One degree on the Celsius scale is not equal to one degree on the Fahrenheit scale. A 1 °C change equals a 1.8 °F change. The scales also start at different zero points: 0 °C = 32 °F, not 0 °F.
How much is 1 °C to 1 °F?
1 °C converts to 33.8 °F using °F = (1 × 9/5) + 32. The number "1" does not mean the same temperature on both scales - 1 °F is much colder than 1 °C (1 °F ≈ -17.2 °C).
What is 38 °C in Fahrenheit for body temperature?
38 °C = 100.4 °F. That is slightly above normal body temperature and is often considered a low-grade fever in adults. Normal body temperature is about 37 °C (98.6 °F). This is general information, not medical advice.
How to convert 98.6 °F into C?
Use °C = (°F - 32) × 5/9. For 98.6 °F: (98.6 - 32) × 5/9 ≈ 37 °C. That is the widely cited average human body temperature. Enter 98.6 in our Fahrenheit field to see Celsius and other scales instantly.
What temperature is 32 °C in F?
32 °C = 89.6 °F - a very warm day. Do not confuse this with 32 °F, which is the freezing point of water (0 °C). Scale mix-ups are common; our converter labels each unit clearly to avoid errors.
Is 37.8 °C in Fahrenheit a fever?
37.8 °C = 100 °F. Many clinicians treat ≥38 °C (100.4 °F) as a fever in adults, so 37.8 °C is borderline elevated. Symptoms and context matter - contact a healthcare professional for medical guidance.
Is 40 Celsius also 40 Fahrenheit?
No. 40 °C = 104 °F - a high fever and dangerously hot weather. 40 °F ≈ 4.4 °C - above freezing but still cold. The same number on Celsius and Fahrenheit always refers to very different temperatures.
Which is colder, 15 °C or 23 °C?
15 °C is colder than 23 °C. In Fahrenheit that is 59 °F versus 73.4 °F - an 8-degree Celsius difference you can feel outdoors. On the Celsius scale, lower numbers always mean colder temperatures.
What is absolute zero in different units?
Absolute zero is -273.15 °C, -459.67 °F, 0 K, or 0 °R. Temperatures below these values are physically impossible.
Does this converter work offline?
Yes. After the first page load, all conversions run in your browser with no server calls.
How many decimal places can I use?
Choose 0–6 decimal places, or enable scientific notation for very large or small values.