Electronics Engineering Calculators & Converters
ONEIC offers a one-stop collection of free online tools for electronics engineers. Whether you need to decode a 4-band resistor or estimate battery runtime, our calculators are quick and easy to use. Bookmark this page so you always have them at hand.
Online Stopwatch Timer
A precise online stopwatch with start, pause, reset and lap timing functions.
555 Monostable Calculator
Calculate the output pulse width of a 555 timer monostable circuit from the resistor and capacitor values. Formula: T = R × C × 1.1
555 Timer Calculator
Determine the output pulse width of a 555 timer in monostable or astable configuration from your resistor and capacitor values.
555 Timer Frequency Calculator
Determine the output frequency of a 555 timer circuit from the resistor and capacitor values in astable mode.
5-Band Resistor Color Code Calculator
Calculate the resistance value and tolerance of a resistor from its five color bands.
Butterworth Low-Pass Filter Calculator
Calculate the inductor and capacitor values for a Butterworth low-pass filter.
Butterworth High-Pass Filter Calculator
Calculate the inductor and capacitor values for a Butterworth high-pass filter.
Battery Life Calculator
Estimate battery runtime from the battery capacity (mAh) and the device current draw (mA).
Parallel Resistor Calculator
Calculate the total resistance of resistors connected in parallel.
Wavelength-Frequency Converter
Convert between wavelength and frequency for electromagnetic waves.
Differential Amplifier Calculator
Calculate the gain and output voltage of a differential amplifier circuit.
Length Unit Converter
Convert between metric and imperial length units, including kilometers, meters, centimeters, miles, yards, feet and inches.
MOSFET Snubber Circuit Calculator
Calculate the parameter values for a MOSFET snubber (buffer) circuit.
Supercapacitor Backup Time Calculator
Calculate the backup run time for trickle-charged RTC circuits from the supercapacitor voltage, capacitance and discharge current.
Hysteresis Comparator Calculator
Calculate the resistor ratio, reference voltage or threshold voltages of a hysteresis comparator.
Capacitor Charge Time Calculator
Calculate the time required for a capacitor to charge to a specified voltage.
Series Resistor Calculator
Calculate the total resistance of resistors connected in series.
Magnetic Flux Density Calculator
Calculate the magnetic flux density in a magnetic core.
Ohm’s Law Calculator
Calculate the relationships between current, voltage, resistance and power in resistive circuits using Ohm’s law.
Band-Pass Filter Calculator
Calculate the center frequency and bandwidth parameters of a band-pass filter.
Single-Layer Coil Inductance Calculator
Calculate the inductance of a single-layer air-core coil.
dBV Calculator
Convert between dBV and voltage values.
dBm to Watts Converter
Convert RF power between dBm and watts quickly.
DC Circuit Calculator
Calculate voltage, current, resistance and power in direct current (DC) circuits.
Parallel Inductor Calculator
Calculate the total inductance of inductors connected in parallel.
Inductance Unit Converter
Convert between henry (H), millihenry (mH), microhenry (µH) and other inductance units.
Inductor Reactance Calculator
Calculate the inductive reactance of an inductor at a specified frequency.
Motor Power Calculator
Calculate the current, voltage and power parameters of an electric motor.
Reactance Calculator
Calculate the reactance or susceptance magnitude of an inductor or capacitor at a specified frequency.
Capacitor Time Constant Calculator
Calculate the RC discharge time constant and the stored energy of a capacitor online.
Wire Voltage Drop Calculator
Calculate the voltage drop in a circuit from the cable parameters.
VSWR Calculator
Calculate the voltage standing wave ratio (VSWR) and return loss of a transmission line.
Electronic Crossover Calculator
Calculate the crossover frequency and component values for an electronic crossover network.
Resistor Current & Voltage Calculator
Calculate the current, voltage and power in a resistor circuit step by step using Ohm’s law.
Voltage Divider Calculator
Determine the output voltage of a voltage divider from the input voltage and the resistor values.
Resistance Unit Converter
Convert between ohms (Ω), kilohms (kΩ), megohms (MΩ) and other resistance units.
Multi-Layer Coil Inductance Calculator
Calculate the inductance of multi-layer coils.
ERP/EIRP Calculator
Calculate the effective radiated power (ERP) and the equivalent isotropically radiated power (EIRP).
LED Current Limiting Resistor Calculator
Calculate the current-limiting resistor value and its power rating for LED circuits.
Air Flow Calculator
Calculate air volume and air velocity parameters for cooling design.
FM/TV Frequency Converter
Convert between FM broadcast frequencies and TV channel frequencies.
Inductive Reactance Calculator (XL)
Calculate the inductive reactance XL = 2πfL from the frequency and the inductance.
Advanced Scientific Calculator
A scientific calculator supporting trigonometric, logarithmic, exponential and factorial functions.
High-Frequency Filter Parameter Calculator
Calculate the characteristic parameters of high-frequency filters.
Power Unit Converter
Convert between watts (W), kilowatts (kW), horsepower (HP) and other power units.
Energy Unit Converter
Convert between BTU, joules (J), calories and other energy units.
Constant Current Source Calculator
Calculate the resistor value and the Q1 power dissipation of a constant current source.
Ring Voltage-Control Circuit Calculator
Calculate the parameters of the ring voltage-control circuit.
Fahrenheit to Celsius Converter
Convert freely between Celsius and Fahrenheit temperatures.
Wheatstone Bridge Calculator
Calculate the bridge voltage or the unknown resistance of a Wheatstone bridge.
J-Antenna Calculator
Calculate the segment lengths of a J-type antenna.
Polyester Capacitor Code Calculator
Decode the marking codes printed on polyester capacitors.
Molecular Weight Calculator
Enter a chemical formula to compute its molecular weight, with support for every element in the periodic table.
RPN Scientific Calculator
A scientific calculator based on reverse Polish notation with trigonometric, logarithmic, factorial and memory functions.
KB/GB Data Unit Converter
Convert between KB, MB, GB, TB and other data storage units.
Air-Core Inductor Calculator
Calculate the inductance of air-core coils.
LC Circuit Frequency Calculator
Calculate the resonant frequency of an LC tank circuit.
LED Power Calculator
Calculate the power consumption and brightness parameters of LEDs.
LED Series Resistor Calculator
Determine the correct series resistor from the supply voltage, forward voltage and forward current of an LED.
Li-Mn Rechargeable Battery Calculator
Calculate the charge and discharge parameters of lithium-manganese rechargeable batteries.
LM117/LM317 Voltage Calculator
Calculate the output voltage and resistor values for LM117/LM317 linear regulators.
Helical Coil Inductance Calculator
Calculate the inductance of helical (spiral) coils.
MC34063 Calculator
Calculate the external component values for the MC34063 switching regulator IC.
Area Unit Converter
Convert between different area units, including square meters, acres and hectares.
Electrical Power Calculator
Calculate the electrical power in a circuit online.
Series Capacitor Calculator
Calculate the total capacitance of capacitors connected in series.
Op-Amp Gain Calculator
Calculate the voltage gain of an operational amplifier circuit.
Parallel Plate Capacitor Calculator
Calculate the capacitance of a parallel plate capacitor.
Frequency Unit Converter
Convert between different frequency units, from hertz to gigahertz.
Preamplifier Design Calculator
Design the parameters of a preamplifier circuit.
Chebyshev Low-Pass Filter Calculator
Calculate the inductor and capacitor values for a Chebyshev low-pass filter.
Chebyshev High-Pass Filter Calculator
Calculate the inductor and capacitor values for a Chebyshev high-pass filter.
Pneumatic Cylinder Pressure Calculator
Calculate the pressure and force parameters of a pneumatic cylinder.
RC Circuit Calculator
Calculate the time constant, cutoff frequency and other parameters of an RC circuit.
RC Filter Cutoff Frequency Calculator
Calculate the cutoff frequency of an RC low-pass or high-pass filter.
RC Time Constant Calculator
Calculate the time constant τ = RC of an RC circuit.
RTC Backup Capacitor Calculator
Calculate the backup capacitor value and the hold-up duration for real-time clock (RTC) circuits.
Trigonometric Function Calculator
Calculate 12 trigonometric functions, including sin, cos, tan, csc, sec and cot.
Transistor Switch Saturation Calculator
Calculate the saturation conditions when using a bipolar transistor as a switch.
Transistor Bias Calculator
Calculate the bias point parameters of a bipolar transistor amplifier circuit.
4-Band Resistor Color Code Calculator
Calculate the resistance value of a 4-band resistor from its color rings.
Data Converter Jitter Calculator
Calculate the theoretical SNR and ENOB caused by clock jitter in data converters.
DAC Calculator
Calculate the resolution and output voltage of digital-to-analog converters (DAC).
4-Band Resistor Calculator
Calculate the resistance value and tolerance of a resistor from four color bands.
PLL Calculator
Calculate the parameters of phase-locked loop (PLL) circuits.
Iron Powder Toroid Core Calculator
Calculate the inductance, turns and AL value of iron powder toroidal cores.
Ferrite Toroid Core Calculator
Calculate the inductance, turns and AL value of ferrite toroidal cores.
Volume Unit Converter
Convert between milliliters, fluid ounces, liters, gallons and other volume units.
Trap Antenna Design Calculator
Calculate the trap coils and the segment parameters of a trap antenna.
MSP430 UART Register Calculator
Calculate the UART baud rate registers and the baud error percentage for MSP430 microcontrollers.
Microstrip Line Impedance Calculator
Calculate the characteristic impedance of PCB microstrip transmission lines.
Temperature Unit Converter
Convert between Celsius, Fahrenheit and Kelvin temperatures.
Zener Diode Calculator
Calculate the parameters of Zener diode voltage regulator circuits.
Zener Current-Limiting Resistor Calculator
Calculate the current-limiting resistor value and its power dissipation for Zener diode regulators.
Coherent Sampling Calculator
Calculate the coherent sampling frequency and the coherent input frequency for FFT analysis.
Star (Wye) Load Calculator
Calculate the voltage and current of star (Y) connected three-phase loads.
IC Thermal Resistance Calculator
Calculate the thermal resistance and heat dissipation parameters of integrated circuits.
Pressure Unit Converter
Convert between psi, bar, kg/cm², pascal and other pressure units.
Speaker Crossover Calculator
Calculate the capacitor and inductor values for loudspeaker crossover networks.
Active Speech Filter Designer
Design the parameters of active speech (voice-band) filter circuits.
Square Wave Low-Pass Filter Calculator
Calculate the capacitor and resistor values for a square wave low-pass filter.
Square Wave High-Pass Filter Calculator
Calculate the capacitor and resistor values for a square wave high-pass filter.
Z/S/Y/A Parameter Calculator
Calculate the Z, S, Y and A parameters of two-port networks.
Cube Root Calculator
Calculate the cube root — or the cube — of any number online.
Weight Unit Converter
Convert between different weight units, including kilograms, pounds and ounces.
Byte Unit Converter
Convert between B, KB, MB, GB, TB and other data storage units.