Electronics & RF calculators
Choose a task below. Check each calculator’s assumptions and units before using its result.
Free EV Home Charging Time & Circuit Breaker Calculator
Calculate Level 1 and Level 2 EV charging hours, added miles of range per hour, required NEC circuit breaker ampacity, and session charging cost.
Free Ferrite Toroid Core Inductance & Turns Calculator
Calculate required turns (N) for target inductance (µH), single-layer wire fit, and peak AC magnetic flux density (Gauss) for ferrite and iron powder cores.
Free Flyback RCD Clamp Snubber Calculator
Calculate clamp resistor resistance & power (Watts), capacitor value (nF), and peak MOSFET Vds voltage stress from transformer primary leakage inductance.
Free Flyback SMPS Transformer Calculator
Calculate primary inductance (Lp), peak switch current, primary-to-secondary turns ratio, and magnetic core air gap length for isolated power supplies.
Free Flyback Transformer Primary Inductance Calculator
Calculate primary inductance (Lp), peak primary current, turns ratio, and core energy storage for DCM/CCM flyback power supplies.
Free H-Bridge Bootstrap Capacitor Calculator
Size high-side gate driver bootstrap capacitors (Cboot), calculate peak gate charge requirements, verify low-side refresh time, and select bootstrap diodes for motor drives and inverters.
Free Half-Wave Dipole & Quarter-Wave Antenna Calculator
Calculate precision element wire lengths, end-effect velocity shortening (K-factor), and feedpoint impedance for HF, VHF, and UHF antennas.
Free Half-Wave Dipole Antenna Calculator
Calculate exact physical antenna wire lengths, quarter-wave radiator legs, end-effect velocity reduction, and feedpoint impedance.
Free Heat Sink Thermal Resistance Calculator
Calculate required heatsink thermal rating (θsa in °C/W), junction temperature, and forced-air airflow margins for power electronics.
Free Inductor Core Saturation Current Calculator
Calculate peak saturation current (Isat), core magnetic flux density (Bmax in Tesla), and required air gap to prevent magnetic core saturation.
Free Instrumentation Amplifier Gain Resistor Calculator
Calculate external gain-setting resistance (Rg), voltage gain, output swing, input common-mode voltage range, and resistor-tolerance CMRR for in-amp ICs and discrete circuits.
Free Interdigital Bandpass Filter Calculator
Synthesize quarter-wave interdigital bandpass filters. Calculate even and odd mode impedances ($Z_{0e}, Z_{0o}$), resonator bar spacings, and input tapping height.
Free Inverting Buck-Boost Converter Calculator
Size power inductors, calculate switch duty cycle, peak inductor current, and switch voltage stress (Vin + |Vout|) for negative voltage power supplies.
Free LED Series-Parallel Resistor Calculator
Calculate ballast resistor values, resistor wattage derating, branch currents, and total electrical efficiency for LED arrays.
Free Log-Periodic Dipole Array (LPDA) Calculator
Design ultra-wideband log-periodic dipole arrays. Calculate geometric scale factors (τ, σ), dipole element lengths, feeder boom spacing, and directivity gain.
Free Microstrip Patch Antenna Calculator
The 310th Tool Milestone! Calculate physical patch width (W), resonant length (L), effective dielectric constant (εeff), and 50Ω inset feed notch depth.
Free MOSFET Gate Resistor & Switching Loss Calculator
Size external gate resistors ($R_G$) and calculate Miller plateau transition times ($t_r, t_f$), turn-on/turn-off switching energy, conduction losses, and driver power dissipation.
Free MOSFET Heatsink Thermal Resistance Calculator
Size heatsinks for power MOSFETs, IGBTs, and regulators (TO-220, TO-247, D2PAK). Calculate junction temperature, total thermal resistance, and heatsink extrusion area.
Free Op-Amp Stability & Phase Margin Calculator
Determine phase margin degradation caused by capacitive loads (CL) and calculate the optimal Riso isolation resistor and dual-feedback compensation.
Free Optocoupler CTR Aging & LED Drive Calculator
Calculate optocoupler LED forward drive current ($I_F$), pull-up load resistor ($R_L$), temperature derating, and long-term CTR aging degradation to guarantee collector saturation.
Free PCB Coplanar Waveguide Impedance Calculator
Calculate characteristic impedance (Z0), effective dielectric constant (εeff), and propagation delay for Coplanar Waveguide with Ground (CPWG).
Free PCB Microstrip Impedance Calculator
Calculate characteristic trace impedance (Z0), effective dielectric constant, and propagation delay for surface microstrip RF lines.
Free PCB Via Current & Temperature Calculator
Calculate plated through-hole via ampacity, DC resistance, voltage drop, and Joule heating temperature rise based on IPC-2152 standards.
Free Pi Attenuator Calculator
Calculate exact resistor values (R1, R2, R3), nearest standard 1% resistors, and power dissipation for RF Pi-pad attenuators.
Free PLL Charge Pump & Loop Filter Calculator
Calculate passive 2nd & 3rd order loop filter components ($C_1, R_2, C_2, R_3, C_3$) for integer-N and fractional-N PLL frequency synthesizers to optimize lock time & phase noise.
Free Quarter-Wave Coax Stub Filter Calculator
Calculate precision quarter-wave (λ/4) and half-wave (λ/2) coaxial stub notch filters for ham radio, repeater isolation, and RF harmonic rejection.
Free RC Airplane Wing Loading Calculator
Calculate aerodynamic wing loading, Wing Cube Loading (WCL), flight category envelope, and true stall speed.
Free RC Low-Pass Filter Time Constant Calculator
Calculate RC charge/discharge time constant (τ), -3dB cutoff frequency, step response rise time, and PWM ripple voltage.
Free RC Snubber Circuit Calculator
Calculate snubber capacitance (C_snub), damping resistance (R_snub), ringing frequency, and resistor power dissipation for MOSFET, IGBT, and Triac protection.
Free Rectangular & Circular Cavity Resonator Calculator
Calculate resonant frequencies for TEmnl and TMmnl modes in rectangular and circular cylindrical waveguide cavity resonators, unloaded Q-factor, and skin depth.
Free RF Attenuator Pad Calculator
Calculate exact resistor values for Pi (π) and Tee (T) passive RF attenuator networks with 50Ω and 75Ω impedance matching.
Free RF Diplexer & LC Crossover Filter Calculator
Design lumped-element LC low-pass and high-pass crossover diplexers for shared antenna feedlines (VHF/UHF), port-to-port isolation, and $50\,\Omega$ matching.
Free RF Directional Coupler & Directivity Calculator
Calculate coupled port power, reverse isolation, mainline insertion loss, and return loss/VSWR measurement uncertainty caused by finite coupler directivity.
Free RF Helical Resonator Bandpass Filter Calculator
Design high-Q helical resonator cavity bandpass filters for VHF & UHF repeater front-ends. Calculate cavity shield dimensions, coil turns, and insertion loss.
Free RF Link Budget & Friis Path Loss Calculator
The 300th Tool Milestone! Calculate Free Space Path Loss (FSPL), EIRP, received signal power (Prx), fade margin, and line-of-sight range for wireless links.
Free RF Lumped-Element Phase Shifter Calculator
Calculate exact $L$ and $C$ component values for low-pass (phase delay) and high-pass (phase advance) symmetric T and $\pi$ phase shifting networks matching $50\Omega$ systems.
Free RF Power Attenuator Pad Calculator
Design symmetrical Pi, Tee, and Bridged-Tee RF attenuators. Calculate exact resistor values, standard 1% E96 matches, and thermal power dissipation per element.
Free RF Power Converter
Instant bidirectional conversion between dBm, Watts, RMS Volts, Peak-to-Peak Volts, and receiver S-meter levels across 50Ω and 75Ω systems.
Free RF Skin Depth & AC Conductor Resistance Calculator
Calculate high-frequency skin depth (δ), AC-to-DC resistance ratio (Rac/Rdc), and optimal Litz wire gauge for RF coils and SMPS magnetics.
Free RF Smith Chart Single Stub Matching Calculator
Calculate transmission line tap distance (d) and open or shorted stub length (l) to achieve an exact 50Ω conjugate match on the Smith chart.
Free Sallen-Key Active Filter Calculator
Design 2nd-order active low-pass & high-pass Sallen-Key filters. Size $R_1, R_2, C_1, C_2$ for Butterworth ($Q=0.707$), Bessel ($Q=0.577$), and Chebyshev ($Q=1.0$) alignments.
Free Sallen-Key Active Low-Pass Filter Calculator
Synthesize 2nd-order active low-pass filters: calculate cutoff frequency, quality factor Q, component values, and op-amp GBW margins.
Free Sallen-Key Bandpass Filter Calculator
Design active second-order bandpass filters. Calculate center frequency (f0), quality factor (Q), passband gain, component values, and op-amp bandwidth limits.
Free Schmitt Trigger Threshold & Resistor Calculator
Calculate upper and lower switching thresholds ($V_{UTP}, V_{LTP}$), hysteresis band ($V_H$), and feedback resistors for inverting and non-inverting comparator circuits.
Free SEPIC Converter Sizing Calculator
Size power inductors (L1, L2), AC series coupling capacitor (Cp), peak MOSFET current, and diode reverse voltage for non-inverting buck-boost SEPIC power supplies.
Free Small Magnetic Loop Antenna Calculator
Size compact HF transmitting loops, calculate radiation resistance, antenna Q, 2:1 SWR bandwidth, and determine peak capacitor voltage to prevent high-voltage arcing.
Free Step-Down Buck Regulator Efficiency Calculator
Calculate switching losses, MOSFET conduction losses, inductor DCR heat, and overall DC-DC conversion efficiency.
Free Step-Up Boost Converter Inductor Calculator
Calculate duty cycle, minimum inductance (µH), peak switch current, critical boundary inductance, and output capacitor ripple voltage for DC-DC boost converters.