Free Online Electronics Tools
Explore ideal circuits, component relationships, filters, conversion and signal levels with online electronics calculators.
Choose the right tool
Match the topology before entering values: series and parallel networks, inverting and noninverting stages, and buck and boost converters use different equations. Component ratings, parasitics, protection and measured conditions require separate review.
Available tools
- LED Series Resistor Sizing Calculator
Online led series resistor sizing calculator. Single ideal LED with supplied forward voltage; choose component tolerances separately.
- Series LED String Resistor Calculator
Online series led string resistor calculator. Identical series LEDs; supply must exceed combined forward drop.
- Parallel LED Branch Supply Current
Online parallel led branch supply current. Each branch must already have its own current regulation.
- BJT Saturation Base Resistor Estimate
Online bjt saturation base resistor estimate. Uses supplied forced beta, not a transistor gain guarantee.
- BJT Collector Load Resistor Estimate
Online bjt collector load resistor estimate. DC load-line arithmetic with user-supplied operating point.
- BJT Emitter Resistor Bias Estimate
Online bjt emitter resistor bias estimate. Approximate DC bias; neglects base-current loading and temperature drift.
- Noninverting Op Amp Gain Calculator
Online noninverting op amp gain calculator. Ideal linear amplifier; rail limits and bandwidth excluded.
- Inverting Op Amp Gain Calculator
Online inverting op amp gain calculator. Ideal virtual ground with negative gain.
- Matched Differential Amplifier Output
Online matched differential amplifier output. Requires matched resistor ratios; input common-mode limits excluded.
- Transimpedance Amplifier Output Estimate
Online transimpedance amplifier output estimate. Ideal inverting current-to-voltage conversion with virtual ground.
- Ideal Op Amp Integrator Ramp
Online ideal op amp integrator ramp. Constant input over the interval; saturation and leakage excluded.
- Ideal Op Amp Differentiator Output
Online ideal op amp differentiator output. Input is voltage slope, not instantaneous voltage.
- Op Amp Gain Bandwidth Estimate
Online op amp gain bandwidth estimate. Single dominant-pole approximation using noise gain when appropriate.
- Sine Wave Slew Rate Frequency Limit
Online sine wave slew rate frequency limit. Large-signal sine limit; small-signal bandwidth may be lower.
- Input Offset Output Error Estimate
Online input offset output error estimate. Input offset only; bias current and drift errors excluded.
- Common Mode Rejection Error Estimate
Online common mode rejection error estimate. CMRR treated as an amplitude ratio at the relevant frequency.
- Resistor Thermal Noise Voltage
Online resistor thermal noise voltage. White Johnson noise over an equivalent rectangular noise bandwidth.
- Capacitive Reactance Calculator
Online capacitive reactance calculator. Ideal capacitor; magnitude excludes the negative imaginary sign.
- Inductive Reactance Calculator
Online inductive reactance calculator. Ideal inductor; parasitic resistance and self resonance excluded.
- RL Low Pass Cutoff Calculator
Online rl low pass cutoff calculator. Series RL network with output across the resistor.
- RC Low Pass Frequency Response
Online rc low pass frequency response. Unloaded first-order RC low pass.
- RC High Pass Frequency Response
Online rc high pass frequency response. Unloaded first-order RC high pass.
- Series RLC Quality Factor Calculator
Online series rlc quality factor calculator. Ideal series RLC with all loss represented by R.
- Series RLC Damping Ratio Calculator
Online series rlc damping ratio calculator. Linear series RLC; unity is critical damping.
- Series RLC Half Power Bandwidth
Online series rlc half power bandwidth. Ideal series resonator bandwidth in hertz.
- Inductor Stored Energy Calculator
Online inductor stored energy calculator. Constant linear inductance; magnetic saturation excluded.
- 555 Astable Timing Calculator
Online 555 astable timing calculator. Standard two-resistor astable with ideal one-third and two-thirds thresholds.
- 555 Monostable Pulse Width Calculator
Online 555 monostable pulse width calculator. Ideal charging from zero to two-thirds supply.
- PWM Average and RMS Voltage
Online pwm average and rms voltage. Ideal two-level waveform; average is not RMS.
- ADC Quantization Step Calculator
Online adc quantization step calculator. Ideal unipolar full-scale span divided into 2^N bins.
- Ideal Quantization SNR Calculator
Online ideal quantization snr calculator. Ideal uniform quantizer driven by a full-scale sine.
- Ideal DAC Code to Voltage Calculator
Online ideal dac code to voltage calculator. Unipolar binary DAC with 2^N denominator convention.
- ADC Input Divider Headroom
Online adc input divider headroom. Ideal divider; protection, settling and ADC loading excluded.
- Linear Regulator Heat Dissipation
Online linear regulator heat dissipation. Steady DC estimate without reverse current or dropout modeling.
- Junction Temperature from Thermal Resistance
Online junction temperature from thermal resistance. Single steady-state thermal resistance model; no safety rating inferred.
- Heatsink Thermal Resistance Budget
Online heatsink thermal resistance budget. Positive remaining thermal budget only; airflow conditions must match ratings.
- MOSFET Resistive Conduction Loss
Online mosfet resistive conduction loss. Current is RMS during on-time; temperature-dependent resistance supplied separately.
- MOSFET Gate Drive Power Estimate
Online mosfet gate drive power estimate. Average charge-delivery power; driver and gate dissipation partition excluded.
- Diode Forward Conduction Heat
Online diode forward conduction heat. Current is average during conduction; reverse recovery excluded.
- Full Wave Rectifier Ripple Estimate
Online full wave rectifier ripple estimate. Small-ripple capacitor-input approximation, not a mains construction guide.
- Bridge Rectifier No Load Peak Estimate
Online bridge rectifier no load peak estimate. Sinusoidal isolated secondary; regulation and load sag excluded.
- Zener Series Resistor Current Budget
Online zener series resistor current budget. DC nominal-point estimate; tolerance and fault conditions excluded.
- Ideal Buck Converter Duty Ratio
Online ideal buck converter duty ratio. Continuous-conduction ideal step-down converter.
- Ideal Boost Converter Duty Ratio
Online ideal boost converter duty ratio. Continuous-conduction ideal step-up converter.
- Buck Inductor Ripple Sizing
Online buck inductor ripple sizing. Ideal CCM buck; saturation, tolerance and compensation require separate review.
- Boost Inductor Ripple Sizing
Online boost inductor ripple sizing. Ideal CCM boost with supplied inductor ripple target.
- Buck Output Capacitor Ripple Estimate
Online buck output capacitor ripple estimate. Triangular inductor ripple and approximate worst-case capacitive plus ESR sum.
- Constant Current Hold Up Capacitor
Online constant current hold up capacitor. Constant-current discharge; ESR and leakage excluded.
- Conductor Skin Depth Calculator
Online conductor skin depth calculator. Homogeneous good conductor approximation.
- PCB Trace DC Resistance Estimate
Online pcb trace dc resistance estimate. Uniform rectangular trace; no current-carrying or temperature safety rating.