Electronics
71 free electronics tools in the Calculators & Converters collection — every one runs in your browser with no signup and no uploads.
Three-Phase Voltage Imbalance Calculator
Calculate percent voltage unbalance per NEMA MG1 and flag motor derating requirements.
Audio Transformer Turns Ratio & Impedance
Calculate turns ratio and impedance transformation for audio transformers
Bar Exam MBE & Scaled Score Calculator
Estimate your UBE scaled total from MBE, MEE and MPT performance.
EU Battery Regulation Compliance Checker
Check battery product compliance with EU Regulation 2023/1542
Battery State of Charge (SoC) Estimator
Estimate lead-acid or lithium battery SoC from resting voltage or Peukert-corrected Ah.
Capacitor Code Reference
Decode 3-digit capacitor codes to picofarad values
Control Transformer Sizing Calculator
Size a control power transformer for a control panel load list with inrush allowance.
CTWD / Contact-Tip-to-Work Distance Calculator
Find voltage drop and burnback risk from CTWD change in MIG welding
dB to Voltage Gain Converter
Convert between dB values and voltage gain/attenuation ratios instantly.
Deck Ledger Bolt Calculator
Calculate ledger-to-house bolt count and spacing from deck size
Drone Battery Cell Count & Voltage Calculator
Understand LiPo cell count, nominal, and charged voltage
Emergency Lighting Battery Runtime Calculator
Verify emergency lighting fixture battery runtime meets NFPA 101 90-minute minimum requirement.
HAS-BLED Bleeding Risk Score
Estimate major bleeding risk before anticoagulation in AF
High-Leg Delta Voltage Calculator
Find the wild-leg voltage on a 120/240 V delta service and confirm phase B marking
kVA to Amps Converter
Convert kilovolt-amperes to amps for single-phase, split-phase, and three-phase systems
LED Retrofit Savings Calculator
Calculate annual energy and cost savings when replacing fluorescent or HID fixtures with LED
LED Lighting Savings Calculator
Calculate energy savings and payback from switching to LED bulbs
LiPo Battery Capacity & Flight Time Calculator
Calculate RC/drone flight time from battery capacity and current draw
Medium-Voltage Cable Sizing Calculator (5–35 kV)
Size MV feeder cables for shielded 5 kV–35 kV systems with ampacity and voltage-drop check.
Power Factor Correction Capacitor Calculator
Size a capacitor bank to correct power factor from a measured PF to a target PF
PV String Voc Temperature Correction Calculator
Correct PV module open-circuit voltage for minimum site temperature per NEC 690.7
RE100 Renewable Energy Pledge Progress Calculator
Track annual renewable energy percentage progress toward a 100% RE target
Resistor Color Code Chart
Decode 4, 5, and 6 band resistor color codes instantly
Solar + Battery Hybrid System Sizing Calculator
Jointly size solar array, battery bank and hybrid inverter for a self-consumption system.
Sealed Subwoofer Box Volume Calculator
Size a sealed sub box from Thiele-Small parameters and read its Qtc and Fc.
Transformer kVA Calculator
Determine required transformer kVA from load amps, voltage, and phase
Transformer Efficiency & No-Load Loss Calculator
Efficiency at partial load and annual no-load energy from core-loss spec
Underground Conduit Burial Depth Checker (NEC 300.5)
Verify NEC Table 300.5 minimum burial depth for conduit and direct-buried cable by method.
Wire Gauge Selector
Choose the correct AWG or kcmil conductor for any load current with ampacity derating
Resistor Color Code Calculator
Decode 4-band resistor colour bands to ohms.
Decibel (dB) Calculator
Convert a power or amplitude ratio to decibels.
Resistor Color Code Calculator
Decode 4, 5 and 6-band resistors — or work backwards from a value to the colours.
Battery Life Calculator
Capacity, load and efficiency → exact runtime hours, minutes and a discharge curve.
Capacitor Code Calculator
3-digit EIA code to capacitance — and back. With tolerance band and voltage rating.
LED Resistor Calculator
Series resistor, nearest E12/E24 value and power rating — instantly.
Voltage Divider Calculator
Solve for Vout, Vin, R1 or R2 — with current, power and full working.
Wire Gauge (AWG) Calculator
AWG to diameter, ampacity with derating, and voltage drop for any run length.
555 Timer Calculator
Astable frequency, duty cycle and monostable pulse width — with full working.
LC Resonant Frequency Calculator
Find the resonant frequency, inductance, or capacitance of any LC tank circuit instantly.
Op-Amp Gain Calculator
Instantly calculate voltage gain, bandwidth and resistor values for any op-amp configuration.
PC Power Supply Calculator
Find the right PSU wattage for your build — CPU, GPU, storage and all.
Voltage Drop Calculator
Calculate voltage drop for any cable run — or find the minimum wire size for a target drop limit.
Battery Runtime Calculator
Peukert-corrected runtime, required capacity, and max load for any battery pack.
Capacitor Charge Calculator
Calculate charge, voltage, capacitance, energy stored and dynamic charge/discharge voltage in an RC circuit.
Capacitor Parallel & Series Calculator
Instantly find the total capacitance of any combination of capacitors in parallel or series.
Decibel Distance Calculator
How loud is a sound at a different distance? Instant inverse-square-law answer.
RC Time Constant Calculator
Calculate τ = R × C, cutoff frequency, and capacitor voltage at any time.
Resistor Parallel Calculator
Equivalent resistance, conductance breakdown and solve-for-missing-R — all in one tool.
UPS Runtime Calculator
How long will your UPS last? Peukert-corrected battery runtime with real efficiency losses.
Resistor Series Calculator
Total resistance, current, voltage drops and power for any series resistor network.
Solar Battery Bank Calculator
Size a solar battery bank with the correct Ah formula — autonomy, DoD, efficiency, cell config.
Dipole Antenna Calculator
Instantly calculate half-wave dipole, quarter-wave monopole, and full-wave loop lengths for any frequency.
Capacitance Calculator
Parallel-plate, charge-voltage, energy stored, RC time constant, series and parallel combinations — all in one tool.
Inductance Calculator
Calculate inductance, reactance, energy, RL time constant and series/parallel combinations.
Resistivity Calculator
Calculate wire resistance, resistivity, length or cross-sectional area — with temperature correction.
Magnetic Force Calculator
Calculate Lorentz force on a charge, on a wire, or between two parallel wires — solve for any variable.
Decibel to Watt Calculator
Convert dB levels to watts (and watts to dB) with full working shown.
ADC Resolution Calculator
Compute LSB voltage, SNR, ENOB, quantisation noise and dynamic range for any ADC.
Amps to Watts Calculator
Convert amps to watts (or watts to amps) for DC, AC single-phase and AC three-phase circuits.
Capacitor Energy Calculator
Calculate the energy stored in a capacitor — plus series/parallel networks and RC discharge power.
Frequency to RPM Calculator
Convert Hz, kHz, rad/s and RPS to RPM — and back — instantly.
kVA to kW Calculator
Convert apparent power to real power instantly — single-phase and three-phase.
kW to kVA Calculator
Convert real power (kW) to apparent power (kVA) using power factor.
Power Dissipation Calculator
Calculate real, apparent and reactive power for DC circuits, AC single-phase and three-phase systems, plus junction temperature from thermal resistance.
Three-Phase Power Calculator
Calculate kW, kVA, kVAR, current and voltage for balanced three-phase AC systems.
Voltage Divider Output Calculator
Compute loaded and unloaded Vout, loading error, power, and nearest E-series resistor.
Watts to Amps Calculator
Convert watts to amps for DC, single-phase AC, and three-phase AC circuits.
Wire Resistance Calculator
Calculate conductor resistance, voltage drop and power loss for any material, length and cross-section.
Conduit Fill Calculator
Check NEC conduit fill compliance — pick a conduit, add wires, get the fill percentage instantly.
Motor FLA Calculator
Calculate full load amperes for single-phase and three-phase AC motors.
PWM Duty Cycle Calculator
Instantly compute duty cycle, frequency, t-on, t-off, period, average voltage, RMS voltage, and power for any PWM signal.