1) Enter the system impedance and required attenuation then then press "Calculate" below to obtain the ideal resistor values.

System impedance:   Ohms Ideal series resistor:   Ohms
Required attenuation:   dB Ideal shunt resistor:   Ohms
 
2) Change the Preferred Resistor Values to those available then press " Calculate" below to get the resulting attenuator parameters.
 
Preferred series resistor:   Ohms Attenuation:   dB
Preferred shunt resistor:   Ohms Input Impedance:   Ohms
Reflection Coefficient: 
VSWR: 
Return Loss:   dB