Softonic

Celsius to Fahrenheit Converter

Step 1 / 4 Celsius to Fahrenheit

0°C equals 32°F (water freezing), 100°C equals 212°F (water boiling at sea level), and °F = °C × 9/5 + 32 covers every value in between. Enter any Celsius temperature for weather, body temperature, oven settings or cold-storage specs, then get the Fahrenheit equivalent plus Kelvin for scientific context. The reverse direction works too.

How Celsius to Fahrenheit conversion works

  1. 1

    Enter a Celsius value

    Use any numeric input, including negative temperatures. −40 is the point where both scales show the same number.

  2. 2

    Apply the formula

    °F = (°C × 9/5) + 32, the same as °F = °C × 1.8 + 32.

  3. 3

    Read Fahrenheit and Kelvin

    Kelvin is also shown with K = °C + 273.15 for scientific context.

  4. 4

    Switch direction

    Use the reverse calculation when needed: °C = (°F − 32) × 5/9.

Quick reference

Celsius Fahrenheit What it means
−40°C −40°F Scales cross (same value)
−18°C 0°F Very cold winter weather
0°C 32°F Water freezes
10°C 50°F Cool spring day
20°C 68°F Comfortable room temperature
25°C 77°F Warm summer day
30°C 86°F Hot summer day
37°C 98.6°F Human body temperature
38°C 100.4°F Low-grade fever
40°C 104°F High fever, heatwave
100°C 212°F Water boils (sea level)
180°C 356°F Common oven setting
200°C 392°F Hot oven for roasting
220°C 428°F Very hot oven or pizza setting

Why two scales?

  • Celsius (Anders Celsius, 1742): the everyday metric temperature scale in most countries. Water freezes at 0°C and boils at 100°C at standard pressure.
  • Fahrenheit (Daniel Fahrenheit, 1724): still common for everyday weather in the United States and a few other markets. On the modern scale, water freezes at 32°F and boils at 212°F.

Kelvin is the SI base unit for thermodynamic temperature. Celsius is convenient for daily life and science communication because each Celsius degree has the same size as one kelvin.

Mental math shortcuts

  • Rough weather check: double the Celsius value and add 30. 20°C becomes about 70°F, while the exact value is 68°F.
  • Hot-weather anchors: 30°C = 86°F, 32°C is about 90°F, and 35°C = 95°F. Memorise these and interpolate.
  • −40 crossover: the only temperature where both scales match.
  • Body temperature: 37°C is about 98.6°F. Readings vary by person, measurement site and time of day.

Kelvin also shown

Kelvin = Celsius + 273.15. It is used in physics and chemistry and starts at absolute zero (−273.15°C). By convention, write “300 K”, not “300°K”.

Frequently Asked Questions

The relationship is exact: °F = °C × 9/5 + 32. The tool displays rounded results, so very long decimals may be shortened for readability.

It’s the only temperature where Celsius and Fahrenheit give the same number. Solving C = F in the conversion formula gives C = −40.

Kelvin is the SI base unit for thermodynamic temperature. Celsius is widely used for everyday temperatures and scientific communication; Fahrenheit is mainly an everyday scale in the United States.

98.6°F is 37°C converted to Fahrenheit. Both are reference averages, and normal body temperature varies roughly from 36.1-37.2°C (97-99°F) depending on the person, time of day and measurement site.

Related Tools

BMI Calculator

Calculate body mass index from height and weight. Shows WHO category, healthy-weight range and limitations of BMI.

GPA Calculator

Calculate grade point average from letter grades and credit hours. Supports US 4.0 and 5.0 honors scales with the standard A/B/C/D letter table.

Inflation Calculator

Calculate the equivalent purchasing power of a dollar across any two years using historical CPI data from 1913 to today.

Scientific Calculator

Full scientific calculator with trig, log, exponents, factorial, memory, parentheses and DEG/RAD toggle. Runs in your browser.

Binomial Probability Calculator

Compute exact, cumulative and tail probabilities for a binomial distribution. Enter n trials, p success rate and k successes.

Calorie Calculator

Estimate daily calorie needs for your goal using Mifflin-St Jeor BMR and activity factors. Includes deficit and surplus targets.