Free online unit converter covering length, weight, temperature, area, volume, time, and speed. Enter a value in any field and all other units update instantly. Supports metric and imperial units including Chinese units (Mu, Jin) and special units like Mach and speed of light.
❓ FAQ
What are the temperature conversion formulas?
Celsius to Fahrenheit: °F = °C × 9/5 + 32. Fahrenheit to Celsius: °C = (°F − 32) × 5/9. Celsius to Kelvin: K = °C + 273.15. Absolute zero is −273.15°C (0 K), the theoretical minimum temperature.
What is the difference between imperial and metric units?
The metric (SI) system is decimal-based, making conversions straightforward (e.g. 1 km = 1000 m). Imperial units have irregular conversion factors (e.g. 1 mile = 1760 yards = 5280 feet). The US still uses imperial units in daily life; most other countries use metric.
How do I convert acres to hectares?
1 hectare = 2.471 acres; 1 acre ≈ 0.4047 hectares. The Chinese unit Mu (亩) ≈ 666.67 m² ≈ 0.0667 hectares, still widely used in Chinese agriculture and real estate.
What is a Mach number?
Mach number is the ratio of an object's speed to the local speed of sound. At sea level, 15°C, the speed of sound is approximately 340.29 m/s (1224 km/h). Mach 1 = the speed of sound; above Mach 1 is supersonic; above Mach 5 is hypersonic.