Temperature Converter

Use our free temperature converter to switch between Fahrenheit, Celsius, and Kelvin — the three scales referenced across US and international construction specs. Enter a temperature in Fahrenheit and see the Celsius and Kelvin equivalents instantly. It's built for checking concrete curing windows, asphalt paving and compaction temperatures, and international material specs written in Celsius or Kelvin.

How to use this calculator.

1. Enter a temperature in Fahrenheit. Type the value into the field above. The default is 72°F.
2. Read the Celsius result. This updates automatically and is the scale most international specs and imported equipment use.
3. Read the Kelvin result. This is the absolute scale used in scientific work and some engineering specs.
4. Check it against a spec range. Compare the converted value to the minimum and maximum temperature called for in your material spec, such as an asphalt compaction range.
5. Re-check if conditions change. Ambient and material temperatures shift throughout the day — recheck before placement if there's a gap between mixing and paving.

How do you calculate temperature conversions?

Celsius is calculated from Fahrenheit using an offset and a scaling factor; Kelvin is then a simple offset from Celsius.

Celsius = (Fahrenheit − 32) × 5 ÷ 9

Kelvin = Celsius + 273.15

Where:

• Fahrenheit: The temperature you enter.
• 32: The offset between the Fahrenheit and Celsius zero points.
• 5 ÷ 9: The scaling factor between the size of a Fahrenheit degree and a Celsius degree.
• 273.15: The offset between the Celsius scale and absolute zero (0 K).

Example calculation.

Convert an asphalt paving temperature of 300°F to Celsius and Kelvin.

1. Fahrenheit to Celsius: (300 − 32) × 5 ÷ 9 = 268 × 5 ÷ 9 = 148.9°C
2. Celsius to Kelvin: 148.9 + 273.15 = 422.0 K

Result: 300°F equals 148.9°Cor 422.0 K. Hot mix asphalt should arrive at the job site between 149 and 163°C (300–325°F).

Tips from the field.

• Concrete curing is temperature-sensitive. Concrete should be placed when the ambient temperature is between 10 and 32°C (50–90°F). Below 4°C (40°F), hydration slows significantly and cold-weather procedures are required.
• Asphalt compaction temperature is critical. Hot mix asphalt must be compacted while above 85°C (185°F). Below this — called the cessation temperature — the mix becomes too stiff to reach proper density.
• Kelvin has no negative values. Zero Kelvin is absolute zero, equal to −273.15°C or −459.67°F, the theoretical point where all molecular motion stops.
• Water's reference points are a good sanity check.Water freezes at 32°F (0°C, 273.15 K) and boils at 212°F (100°C, 373.15 K) at sea level. Use these to spot-check a conversion at a glance.

Disclaimer: Conversions use standard formulas. For scientific or engineering applications requiring extreme precision, use calibrated instruments and verify against certified reference standards. Temperature conversion formulas assume ideal conditions.