Temperature Converter Tool

How three-way conversion works

Rather than storing six separate formulas (one per direction), the script always converts your input to Celsius first, then from Celsius to your target unit. That's why the two dropdowns can be set to any combination without extra code paths.

The three conversions to Celsius

• From Fahrenheit: °C = (°F − 32) × 5/9
• From Kelvin: °C = K − 273.15
• From Celsius: no change

Worked example: Celsius to Kelvin

Enter 100 with "Celsius" as the source and "Kelvin" as the target: 100 + 273.15 = 373.15 K — the boiling point of water at sea level, and also why 0 K ("absolute zero") is −273.15°C.

Fixed points across all three scales

Kelvin has no negative values in physical use — 0 K is the coldest temperature theoretically possible — which is why the Kelvin scale skips the ° symbol entirely; it's just "K."