Celsius to Fahrenheit: The Essential Temperature Cheat Sheet for Cooking, Travel, and Weather

You’re reading a recipe that says “bake at 180°C” but your oven only displays Fahrenheit. Your weather app shows 35°C in Rome but you think in Fahrenheit. A fever is 100.4°F but your thermometer reads 38°C. Temperature conversions are the most common international math problem — and most people get them wrong because they rely on vague mental estimates.

Use the temperature converter at TodayCalculator for instant, exact conversions. But here’s the cheat sheet with the numbers you actually need — plus the simple formulas to do it in your head.

The Quick Conversion Formulas

Celsius to Fahrenheit: °F = (°C × 9/5) + 32
Fahrenheit to Celsius: °C = (°F − 32) × 5/9

Mental shortcut (within 0.5°F accuracy): °F ≈ (°C × 2) + 30
Example: 20°C → (20 × 2) + 30 = 70°F (actual: 68°F, off by 2°F — close enough for travel and weather)

The Essential Temperature Cheat Sheet

These are the temperatures you’ll actually encounter in daily life — no need to memorize the formula each time:

Scenario	°C	°F	Context
Freezing point of water	0°C	32°F	Roads start icing below this
Cold winter day	−10°C	14°F	Heavy coat weather
Cool spring morning	10°C	50°F	Light jacket needed
Room temperature	20°C	68°F	Standard indoor comfort
Pleasant outdoor day	25°C	77°F	Perfect for a walk
Hot summer day	30°C	86°F	AC recommended
Heatwave	38°C	100°F	High risk of heat exhaustion
Normal body temperature	37°C	98.6°F	Average adult
Low-grade fever	38°C	100.4°F	Fever threshold
High fever (seek care)	39.5°C	103°F	Adult emergency threshold
Boiling point of water	100°C	212°F	At sea level

Oven Temperature Conversions for Cooking

International recipes are the most common place you’ll need temperature conversions. Here’s the standard oven settings:

Oven Setting	°C	°F	Gas Mark	Common Uses
Very low / warm	110°C	225°F	¼	Gentle warming, meringues
Low	150°C	300°F	2	Slow roasting, braising
Moderate	180°C	350°F	4	Most baking: cakes, cookies, bread
Moderately hot	200°C	400°F	6	Roasting vegetables, chicken
Hot	220°C	425°F	7	Pizza, bread with crisp crust
Very hot	240°C	475°F	9	Broiling, quick sear

The most common conversion: 180°C = 350°F. If you remember nothing else, remember that one. It’s the standard baking temperature for most recipes worldwide.

Travel Temperature Cheat Sheet

Feel	°C Range	°F Range	What to Pack
Freezing	−5°C to 0°C	23°F to 32°F	Heavy coat, gloves, scarf
Cold	0°C to 10°C	32°F to 50°F	Warm jacket, layers
Cool	10°C to 18°C	50°F to 64°F	Light jacket, sweater
Mild	18°C to 24°C	64°F to 75°F	Long sleeves or light layers
Warm	24°C to 30°C	75°F to 86°F	Short sleeves, shorts
Hot	30°C to 35°C	86°F to 95°F	Light clothing, hat, sunscreen
Very hot	35°C+	95°F+	Stay indoors mid-day, hydrate

Why the Two Scales Exist (and Which Countries Use Which)

Fahrenheit was invented in 1724 by Daniel Gabriel Fahrenheit, who set 0°F as the freezing point of a brine solution and 96°F (later adjusted to 98.6°F) as human body temperature. Celsius was invented in 1742 by Anders Celsius, who set 0°C as the boiling point of water and 100°C as the freezing point (it was later reversed).

Today, every country in the world uses Celsius except the United States, the Bahamas, Belize, the Cayman Islands, and Palau. Liberia and the Marshall Islands are in transition. The U.S. remains the only major economy still using Fahrenheit — and it costs the country an estimated $1.2 billion annually in conversion errors, missed export opportunities, and calibration mistakes in international manufacturing (NIST, 2019).

The Bottom Line

For cooking: 180°C = 350°F. For weather: 20°C = 68°F (room temp), 30°C = 86°F (hot), 38°C = 100°F (heatwave). For fever: 38°C = 100.4°F (threshold). For anything else: use the temperature converter at TodayCalculator — it’s instant, accurate, and handles any conversion between Celsius, Fahrenheit, and Kelvin.