Temperature conversion answers two different questions. Exact unit conversion preserves one physical temperature: Fahrenheit equals Celsius multiplied by nine fifths plus 32, and Celsius equals Fahrenheit minus 32 multiplied by five ninths. Recipe tables often answer a practical question instead: which familiar oven dial setting is close enough for ordinary cooking. OvenTemp displays those ideas separately so a rounded pair is never presented as algebraic identity.
Use the rational formula for exact conversion
Starting with 180 °C, the exact calculation is 180 × 9 ÷ 5 + 32 = 356 °F. Going back, 356 − 32, then multiplied by 5 ÷ 9, returns exactly 180 °C. The factors 9/5 and 5/9 matter: a floating approximation or prematurely rounded intermediate value can lose the reversible relationship. OvenTemp keeps canonical Celsius–Fahrenheit arithmetic separate from any kitchen-friendly display choice.
Treat 180 °C ≈ 350 °F as recipe shorthand
Many recipes pair 180 °C with 350 °F because 350 is a familiar dial setting and the difference is usually handled by cooking time, oven variation, and checking doneness. Mathematically, however, 350 °F converts to about 176.7 °C, not 180 °C. The approximation sign is meaningful. Use the practical pair when following a rounded recipe chart, but retain the exact result when precision or reversibility matters.
Let the source recipe decide which value to use
If a recipe supplies both units, use the author’s stated setting rather than recalculating one side. If it supplies only one unit, exact conversion explains the relationship and the practical equivalent helps with a stepped oven dial. Neither number can correct an uncalibrated oven, unusual cookware, altitude, or recipe-specific timing. Observe the food and follow any explicit temperature, fan, rack, and doneness instructions from the recipe or appliance maker.