The kelvin is the primary unit of temperature measurement in the physical sciences, which has the same magnitude as Celsius and is often used in conjunction with the degree Celsius. The unit of Kelvin is based upon the absolute scale. It is one of the seven base units in the International System of Units (SI) and is assigned the unit symbol K. The Formula for converting Kelvin to Celsius is C = K-273. That is, subtracting 273.16 K from the temperature of the triple point of water (0.01 °C) makes absolute zero (0 K) equivalent to -273.15 °C (-459.67 °F).