Celsius to Fahrenheit: The Exact Formula and the Easy Shortcut

How do you convert Celsius to Fahrenheit? The exact formula is °F = (°C × 1.8) + 32, so 25 °C is 77 °F. There's also an easy shortcut you can do in your head: double it and add 30. This video shows where that shortcut comes from, why it's only exactly right at 10 °C, how far it drifts on hot and cold days, and when the difference really matters. Try it yourself: ▶ https://www.metric-conversions.org/temperature/celsius-to-fahrenheit.htm Chapters: 0:00 Intro: 25 °C in Fahrenheit? 0:20 Why the scales differ 0:54 The exact formula 1:27 The quick approximation 2:14 Why it drifts 3:00 Takeaway Sources: • SI Units – Temperature, NIST: https://www.nist.gov/pml/owm/si-units-temperature • NIST Handbook 44 (2024), Appendix C: https://www.nist.gov/document/nist-hb-44-2024-appendix-c-general-tables-units-measurement • Celsius to Fahrenheit conversion calculator: https://www.metric-conversions.org/temperature/celsius-to-fahrenheit.htm • Definitions of signs, symptoms and conditions in ill travelers, CDC: https://www.cdc.gov/quarantine/maritime/definitions-signs-symptoms-conditions-ill-travelers.html • Hyperpyrexia, Cleveland Clinic: https://my.clevelandclinic.org/health/diseases/hyperpyrexia • What is hyperpyrexia?, WebMD: https://www.webmd.com/a-to-z-guides/what-is-hyperpyrexia Have a question? Ask in the comments below.