Electronics
Electronics
Circuit calculators for filters, dividers, LEDs, power, and real component values.
Use these calculators to check circuit values before breadboarding or repair.
Calculations run locally in the browser and produce practical engineering reports.
The preferred-value designer searches E-series parts instead of showing only ideal math.
Electronics tools in this category
8 tools
LC Resonance Calculator
Find the resonant frequency of an LC pair, plus XL, XC, and the net reactance at a test frequency.
Use this tool when Do you need to calculate the resonant frequency of an LC circuit?
- Inductance from nanohenries through henries
- Optional series R for Q and bandwidth
- Net reactance XL minus XC
LED Resistor Calculator
Find the series resistor for one or more LEDs from the supply, the forward drop, the count, and the current.
Use this tool when Do you need to find the correct resistor value for an LED based on source voltage?
- Resistor = (supply − forward × count) / current
- Power = current × current × resistance
- The run stops when the resistor voltage is not positive
Ohm's Law Calculator
Enter any two of voltage, current, resistance, and power, and the page fills in the other two.
Use this tool when Do you need to calculate voltage, current, resistance, or power using Ohm's Law?
- Any two of voltage, current, resistance, and power
- Current units A, mA, and µA
- Resistance units Ω, kΩ, and MΩ
Op-Amp Gain Calculator
Compute ideal inverting or non-inverting op-amp gain from the input resistor and the feedback resistor.
Use this tool when Do you need to calculate the gain of an inverting or non-inverting operational amplifier?
- Inverting and non-inverting modes
- Gain as a ratio and in decibels
- Output voltage when an input voltage is typed
PCB Trace Width Calculator
Estimate an external or internal PCB trace width from current and temperature rise, then the resistance of the length you type.
Use this tool when Do you need to calculate the minimum PCB trace width required for a specific current?
- Current in amps or milliamps
- Copper thickness in ounces, converted at 1.378 mil per ounce
- A note that the result is an estimate
RC High-Pass Calculator
Find the cutoff of a first-order RC high-pass and the gain, attenuation, and phase at the frequency you type.
Use this tool when Do you need to calculate the cutoff frequency of an RC high-pass filter?
- Resistance in ohms, kilohms, or megohms
- Capacitance in picofarads through millifarads
- Gain to four decimals and phase to two decimals
RC Low-Pass Calculator
Find the cutoff of a first-order RC low-pass and the gain, attenuation, and phase at the frequency you type.
Use this tool when Do you need to calculate the cutoff frequency of an RC low-pass filter?
- Defaults of 10 kΩ, 100 nF, and 1000 Hz
- Time constant, reactance, gain, dB, and phase
- Positive R, C, and test frequency required
Voltage Divider Calculator
Compute the unloaded and loaded output of a two-resistor divider, plus the current and the power in each resistor.
Use this tool when Do you need to calculate the output voltage of a resistor divider circuit?
- R1, R2, and an optional load
- Units of ohms, kilohms, and megohms
- Vin, R1, and R2 must be positive
More tools
The rest of the catalogue. Each tool still runs in your browser.
555 Timer Calculator
Calculate astable frequency, duty cycle, charge and discharge time, or monostable pulse width for a 555 timer.
Preferred RC Filter Designer
Find practical E12, E24, or E96 resistor and capacitor pairs for a target RC filter cutoff.
RLC Q Calculator
Calculate resonance, Q factor, and bandwidth for series or parallel RLC circuits.
Wheatstone Bridge Calculator
Calculate Wheatstone bridge differential output, balance point, and excitation-relative error.