They are equal at -40° (minus 40 degrees).
...because if we convert the readings of Celsius and Fahrenheit, we will have:
Celsius to Fahrenheit (-40°C x 9/5) +32 = -72 + 32 = -40°F
Fahrenheit to Celsius (-40°F - 32°) x 5/9 = (-72 )x 5/9 = -40°C
Algebraically (for the numerical value T)
The formula for some identical temperature T would be
T(°F) = T(°C) and T = (9/5 T + 32) yields 4/5 T = -32 and T = -40
(see related question)
The temperature at which both Fahrenheit and Celsius are equal is -40 degrees.
Ovens in America typically display temperatures in Fahrenheit.
0
Behind the value there could be °F for degrees Fahrenheit or °C for degrees Celsius. When it freezes at 0 degrees Celsius it is 32 degrees Fahrenheit. A hot temperature of 40 degrees Celsius is 104 degrees Fahrenheit.
At -40 degrees, Celsius and Fahrenheit are equal. Warmer than that, and Fahrenheit will have the bigger number than Celsius. Cooler than -40 and Celsius will have a bigger number than Fahrenheit.
At -40 degrees.
Fahrenheit and Celsius
You can quickly estimate Fahrenheit temperatures from Celsius by doubling the Celsius temperature and adding 30. This will give you an approximate Fahrenheit equivalent. For example, if it's 20°C, double it to get 40, then add 30 to get 70°F.
There are two reasons for this. The first is that a Fahrenheit degree is smaller than a Celsius degree. Four Celsius degrees is the same size as nine Fahrenheit degrees. The second reason is that 32 degrees Fahrenheit is zero degrees Celsius. If you put those two ideas together you figure out that -40°F = -40°C.
The temperature at which both Fahrenheit and Celsius are equal is -40 degrees.
I suggest you convert each of the Fahrenheit temperatures to Celsius (or the other way round, each of the Celsius temperatures to Fahrenheit), and then compare.
-273.15 Celsius or -459.67 Fahrenheit.
Ovens in America typically display temperatures in Fahrenheit.
0
Temperatures cannot be negative, so it is impossible to measure -85 degrees Fahrenheit or -50 degrees Celsius. All the other temperatures given, -20 degrees Celsius and 545 degrees Fahrenheit, are possible to measure.
1 Fahrenheit degree = 5/9 of one Celsius degrees 1 Celsius degree = 1.8 Fahrenheit degree There is no constant ratio between the °F and °C numbers for the same temperature, because their zeros are at different temperatures. A Celsius number less than -40° is colder than the same Fahrenheit number. A Celsius number more than -40° is warmer than the same Fahrenheit number. And -40° is the same actual temperature in both °F and °C.
Temperatures in that range are associated with stellar fusion, and are usually expressed in Kelvin, which is practically the same as Celsius for those high temperatures. However, 15 million °C would equal 27 million °F. Fahrenheit is almost never used for such high temperatures. Celsius and Kelvin are normally used. But 15 million degrees on the Celsius scale would be approximately 27 million degrees on the Fahrenheit scale.