// Calculators › Signal & Power

Attenuator Calculator

Design Pi and T pad RF attenuators. Enter attenuation and system impedance to get resistor values, or enter resistor values to find attenuation.

// Parameters

Attenuation

dB

System Impedance (Z₀)

Ω

R1 (shunt)

Ω

R2 (series)

Ω

R3 (shunt)

Ω

System Impedance (Z₀)

Ω

⚠ Please check your inputs.

// Results

🔧

Enter parameters and click Calculate

R1 (shunt)—Ω

R2 (series)—Ω

R3 (shunt)—Ω

Attenuation—dB

Insertion Loss—dB

Return Loss (S11)—dB

Power Dissipated—% of Pin

Pi Pad (symmetric, Z₀ matched)
K = 10^(Att/20)
R1 = R3 = Z₀·(K+1)/(K−1)
R2 = Z₀·(K²−1)/(2K)

Tee Pad (symmetric, Z₀ matched)
K = 10^(Att/20)
R1 = R3 = Z₀·(K−1)/(K+1)
R2 = 2·Z₀·K/(K²−1)