Professional Electrical
Engineering Calculators
50 calculators across 5 engineering disciplines. Instant results, built-in formulas, offline-first. Built for engineers, technicians, and students.
50
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5
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Offline
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Built for Engineers
Everything you need for electrical engineering calculations on the go.
50 Professional Calculators
Five complete engineering disciplines in one app — Basic Circuits, AC Analysis, Components, Power Systems, and Electronics. From Ohm's Law to Op-Amp Gain.
Visualize Your Results
Every calculator generates charts and detailed output in the Report tab, giving you a clear picture of your calculations beyond just the numbers.
Export & Share Anywhere
Export to PDF, Excel, or CSV with a single tap. Share results via email directly from the app. PRO feature — unlock with a one-time $3.99 upgrade.
Fully Offline
All 50 calculators run entirely on-device. No internet required for calculations. Your history is stored locally in a Room database and never transmitted.
50 Professional Calculators
Select a category to explore all calculators. PRO badges indicate premium tools.
Ohm's Law, Power, Energy, Cost
Ohm's Law Calculator
Calculate voltage (V = IR), current (I = V/R), and resistance (R = V/I). Ohm's Law fundamentals.
Voltage Calculator
Calculate voltage across components using Ohm's Law and Kirchhoff's Voltage Law (KVL).
Current Calculator
Calculate current in series and parallel circuits. Apply KCL to multi-branch networks.
Resistance Calculator
Calculate total resistance in series (R = R1+R2+...) and parallel (1/R = 1/R1+1/R2+...) circuits.
Power Calculator
Calculate electrical power: P = VI = I²R = V²/R. Supports DC and resistive AC circuits.
Energy Consumption Calculator
Calculate energy consumed: E = P × t (kWh). Estimate device energy usage over time.
Electrical Cost Calculator
Calculate electricity cost: Cost = kWh × Rate. Enter power, hours, and price per kWh.
Watt Calculator
Convert watts to kW, HP, and BTU/hr. Bidirectional power unit conversion for motors and appliances.
Joule Calculator
Calculate energy in joules: J = W × s. Convert between joules, calories, and watt-hours.
Electric Charge Calculator
Calculate charge: Q = I × t. Convert between coulombs, milliampere-hours, and ampere-hours.
Reactance Calculator
Calculate inductive (XL = 2πfL) and capacitive (XC = 1/2πfC) reactance at any frequency.
Impedance Calculator
Calculate total impedance Z = √(R² + X²) for series and parallel RLC circuits.
Power Factor Calculator
Calculate power factor: PF = cos(θ) = P/S. Analyze leading and lagging loads.
Real Power Calculator
Calculate true (real) power P = V × I × cos(θ) for AC circuits in watts and kilowatts.
Reactive Power Calculator
Calculate reactive power Q = V × I × sin(θ) in VAR. Analyze capacitive and inductive loads.
Apparent Power Calculator
Calculate apparent power S = V × I in VA and kVA. Essential for transformer and UPS sizing.
RMS Voltage Calculator
Calculate RMS voltage from peak: Vrms = Vpeak / √2. For sinusoidal and non-sinusoidal waveforms.
RMS Current Calculator
Calculate RMS current: Irms = Ipeak / √2. Convert between peak, peak-to-peak, and RMS values.
Frequency Calculator
Calculate frequency from period: f = 1/T. Convert between Hz, kHz, MHz, and angular frequency.
Phase Angle Calculator
Calculate phase angle θ = arctan(X/R) between voltage and current. Determine leading or lagging.
Resistor Color Code Calculator
Decode 4-band and 5-band resistors. Select band colors for instant resistance, tolerance, and E-series standard value.
LED Resistor Calculator
Calculate the series resistor for an LED: R = (Vs − Vf) / If. Supports multiple LEDs in series.
Capacitor Calculator
Calculate capacitance in series and parallel. Convert between F, μF, nF, and pF. Charge/discharge curves.
Inductor Calculator
Calculate inductance in series and parallel. Toroidal and solenoid coil inductance calculation.
RC Time Constant Calculator
Calculate RC time constant τ = R × C. Charge/discharge time to 63.2% and 99.3% of Vc.
RL Time Constant Calculator
Calculate RL time constant τ = L/R. Current rise and fall times in inductive circuits.
RLC Resonance Calculator
Calculate resonant frequency f = 1/(2π√(LC)). Series and parallel resonance, bandwidth, Q factor.
Capacitor Energy Calculator
Calculate energy stored in a capacitor: E = ½CV². Supercapacitor and capacitor bank analysis.
Inductor Energy Calculator
Calculate energy stored: E = ½LI². Magnetic field energy in inductors.
Filter Calculator
Design low-pass, high-pass, band-pass filters. Calculate cutoff frequency: fc = 1/(2πRC).
Transformer Calculator
Calculate turns ratio, voltage/current transformation. Np/Ns = Vp/Vs = Is/Ip.
Transmission Line Loss Calculator
Calculate I²R losses in power lines. Voltage drop and power loss over distance.
Voltage Drop Calculator
Calculate voltage drop in cables: Vd = (2 × I × R × L) / 1000. Per NEC guidelines.
Short Circuit Current Calculator
Calculate fault current Isc = V / Z. Symmetrical and asymmetrical fault analysis.
Load Calculator
Calculate total electrical load for residential/commercial. Demand factors per NEC Article 220.
Generator Power Calculator
Size generators for loads. Calculate kVA, kW with power factor. Startup surge consideration.
Motor Current Calculator
Calculate full load amps: I = P / (V × PF × η × √3) for 3-phase motors.
Motor Power Calculator
Calculate motor power, torque, RPM relationships. HP ↔ kW conversion. Efficiency analysis.
Battery Capacity Calculator
Calculate battery capacity in Ah/Wh. Runtime, charge time, series/parallel configurations.
UPS Runtime Calculator
Calculate UPS battery runtime: t = (VA × PF × Eff) / Load. Size UPS for load.
Transistor Bias Calculator
Calculate BJT bias point: IC, VCE, IB for voltage divider bias. Operating point analysis.
Op-Amp Gain Calculator
Calculate gain for inverting (-Rf/Rin) and non-inverting (1 + Rf/Rin) configurations.
Voltage Divider Calculator
Calculate output voltage: Vout = Vin × R2 / (R1 + R2). Find resistor values.
ADC Resolution Calculator
Calculate ADC resolution, step size, and quantization. LSB = Vref / 2^n.
DAC Output Calculator
Calculate DAC output voltage: Vout = (Digital Value / 2^n) × Vref.
Signal Frequency Calculator
Analyze signal frequency, period, wavelength. f = 1/T, λ = c/f.
PWM Duty Cycle Calculator
Calculate duty cycle, average voltage, frequency from on/off times. D = Ton/(Ton+Toff).
Oscillator Frequency Calculator
Calculate oscillator frequency for RC, LC, crystal circuits. f = 1/(2π√(LC)).
Gain Calculator
Calculate gain in dB: Av(dB) = 20 × log10(Vout/Vin). Power gain: 10 × log10(Pout/Pin).
Signal Attenuation Calculator
Calculate signal loss in dB over distance. Attenuation = 10 × log10(Pin/Pout).
FREE FEATURE
Decode Any Resistor in Seconds
Select band colors for a 4-band or 5-band resistor and instantly get the resistance value, tolerance, and E-series closest standard value. No color chart required — it's built in.
Download Free4-Band: Brown · Black · Red · Gold = 1 kΩ ±5%
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Home — All 50 calculators by category
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Get started with the most essential calculators.
- 20 calculators — 4 from each category
- Ohm's Law, Voltage, Current, Resistance
- Reactance, Impedance, Power Factor, Real Power
- Resistor Color Code, LED Resistor, Capacitor, Inductor
- Transformer, Voltage Drop, Transmission Line Loss, Short Circuit Current
- Transistor Bias, Op-Amp Gain, Voltage Divider, ADC Resolution
- Calculation history
- Built-in documentation and formulas
- Ads shown between calculators
- 30 Pro calculators locked
- Export to PDF / Excel / CSV not available
Pro
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One-time purchase · Lifetime access
Unlock every calculator and remove all ads. Forever.
- All 50 calculators unlocked
- Everything in Free
- Power Calculator, Energy Consumption, Electrical Cost
- Joule, Watt, Electric Charge Calculators
- All 6 additional AC Circuit calculators (RMS, Frequency, Phase Angle, etc.)
- RC/RL Time Constants, RLC Resonance, Filter, Energy Calculators
- All Power Systems: Load, Generator, Motor, Battery, UPS
- All Electronics: DAC, PWM, Oscillator, Gain, Signal Attenuation
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- Export results to PDF, Excel, and CSV
- Share results via email
- Priority updates and new features
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Purchases managed securely by Google Play. Restore anytime from Settings inside the app. Price displayed in USD. Local pricing may vary.
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