Temperature: $C = \frac{5}{9}(F - 32)$, $K = C + 273.15$
Logarithmic references: dBm = 10 log10(P / 1 mW); dBmV = 20 log10(V / 1 mV); dBµV = 20 log10(V / 1 µV).
All other conversions use standard linear scale factors relative to a base SI unit.
Linear SI conversion factors; dBm refers to 1 mW, dBmV to 1 mV and dBµV to 1 µV. Logarithmic conversion requires a positive linear quantity. No impedance-dependent power/voltage conversion. Temperature values below absolute zero are rejected. BTU uses the International Table convention; hp is mechanical horsepower. NIST conversion reference.