Temperature Converter: How to Convert Between Celsius, Fahrenheit, and Kelvin with Ease

Temperature conversion is a daily necessity — whether you are baking cookies from an American recipe that calls for 350°F (but your oven uses Celsius), checking whether 30°C in Barcelona requires a jacket (86°F — definitely shorts weather), or running a lab experiment that needs Kelvin. The three most common scales — Celsius, Fahrenheit, and Kelvin — are used for different purposes around the world.

Get instant, accurate conversions with our free Temperature Converter — handles Celsius, Fahrenheit, and Kelvin with one click.

Common Temperature Reference Table

Situation	°C	°F	K
Absolute zero	-273.15	-459.67	0
Coldest recorded on Earth	-89	-128	184
Water freezes / Ice melts	0	32	273.15
Cold winter day	0	32	273.15
Cool spring day	10	50	283
Pleasant room temperature	20	68	293
Warm summer day	30	86	303
Body temperature	37	98.6	310.15
Hot day / heatwave	40	104	313
Water boils (sea level)	100	212	373.15

The Three Conversion Formulas

Celsius to Fahrenheit

Formula: °F = (°C × 9/5) + 32

Example: 25°C = (25 × 9/5) + 32 = 45 + 32 = 77°F. A warm, pleasant day.

Fahrenheit to Celsius

Formula: °C = (°F − 32) × 5/9

Example: 98.6°F (body temp) = (98.6 − 32) × 5/9 = 37°C.

Celsius to Kelvin

Formula: K = °C + 273.15

Kelvin is the SI base unit for temperature, used in science and engineering. Unlike Celsius and Fahrenheit, Kelvin has no negative numbers — 0 K is absolute zero, where molecular motion stops entirely.

Oven Temperature Conversion Guide

This is one of the most common conversion needs. Here is a quick reference for baking and roasting:

Description	°F	°C (Gas Mark)	°C (Fan/Convection)
Very slow / warming	250	120 (1/2)	100
Slow / low	300	150 (2)	130
Moderate	350	180 (4)	160
Moderately hot	375	190 (5)	170
Hot	400	200 (6)	180
Very hot	450	230 (8)	210

Pro tip: Convection (fan-forced) ovens cook about 20°C (36°F) cooler than conventional ovens. If a recipe says 180°C conventional, set a fan oven to 160°C.

Mental Math Shortcuts

C to F quick estimate: Double the Celsius and add 30. (25°C × 2 + 30 = 80°F — close to the exact 77°F)
F to C quick estimate: Subtract 30 and halve. (77°F − 30 ÷ 2 = 23.5°C — close to 25°C)
The -40 crossover: -40°C equals -40°F. The only point where both scales match.
10°C/50°F rule: Every 10°C change equals an 18°F change (because 1°C = 1.8°F).

Real-World Applications

Cooking & baking: European recipes use Celsius (180°C for baking), American recipes use Fahrenheit (350°F). Misreading either ruins the dish.
Weather & travel: 20°C = 68°F (pleasant), 30°C = 86°F (hot), 35°C = 95°F (extreme heat). Pack accordingly.
Health & fever: Normal body temperature is 37°C / 98.6°F. A fever starts at 38°C / 100.4°F.
Science & medicine: Labs use Kelvin for precision. Vaccine storage: 2-8°C (35.6-46.4°F).
HVAC: US thermostats use Fahrenheit; most of the world uses Celsius. A comfortable home is 68-72°F (20-22°C).

For any temperature conversion, bookmark our Temperature Converter for instant results. Also check out our Weight Converter and Volume Converter for other common kitchen and travel conversions.