Circuits And Components
Series and parallel circuit calculators for voltage dividers, resistor networks, LED series resistors, shunts, reactance, capacitors, RC timing, and voltage-drop checks.
Electrical Formulas
Voltage, current, resistance, power, energy, power factor, and cost calculators for basic electrical math.
Subcategories
Power, Energy And Cost
Power factor, reactive power, kWh use, time-of-use cost, fuel cost, and energy savings calculations.
Voltage, Current And Resistance
Ohm law, watts, amps, volts, resistance, current, voltage, and DC power calculations.
Published Calculators
Watts Volts Amps Calculator (Real Power to Current)
Calculate current and apparent power from real power, voltage, phase model, and power factor.
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Voltage From Power And Current Calculator
Calculate ideal voltage from entered real power in watts and current in amperes using direct algebra.
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Voltage Drop Across Resistor Calculator (I x R and Power)
Calculate resistor voltage drop and power dissipation from current and resistance.
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Time-of-Use Electricity Cost Calculator (Peak, Shoulder, Off-Peak)
Calculate time-of-use electricity cost from peak, shoulder, and off-peak kWh, each period rate, and a fixed charge.
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Solar Energy Cost Calculator
Estimate lifetime energy, total cost, and cost per kWh from system cost, annual output, O&M cost, and project lifetime.
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Soft Starter Bypass Calculator
Compare motor running current and a service-factor reference current with an entered soft-starter bypass rating for an early equipment review.
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Sensor Resistor Calculator
Estimate ideal series-resistor headroom, resistance, and dissipation for a defined DC sensor interface.
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Reactive Energy Calculator
Estimate kvarh, kVAh, and phase angle from entered real energy and power factor for preliminary power-factor review.
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Reactance Calculator
Compare XL, XC, and net reactance from entered frequency, inductance, and capacitance for circuit review.
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Power Triangle Angle Calculator
Estimate power factor, reactive-power magnitude, and power-triangle angle from known kW and kVA values, with leading or lagging sign left to external review.
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Power Factor Penalty Calculator
Estimate current and threshold apparent power, excess kVA, and the resulting rate-based charge from entered power-factor and billing assumptions.
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Power From Energy And Time Calculator
Convert watt-hours and elapsed hours into average power in watts and kilowatts without implying peak demand or equipment rating.
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Peak To RMS Voltage Calculator for Sine Waves
Convert peak voltage to RMS and peak-to-peak voltage for a sinusoidal waveform.
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Peak Demand Calculator
Estimate diversified peak demand and compare it with entered service capacity for preliminary load review.
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Operating Cost Comparison Calculator
Compare existing and proposed annual operating costs, annual savings, cost difference, and simple payback from entered energy, rates, fixed costs, and project cost.
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Motor Control Circuit Calculator
Estimate control-circuit VA, current, reserve requirement, transformer margin, and utilization from entered device loads.
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LED Series Resistor Calculator (DC Supply to Resistor Value)
Estimate the current-limiting resistor for a series LED string and show a rounded-up common-value candidate.
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Impedance Magnitude Calculator
Estimate single-frequency AC impedance magnitude, phase angle, and power-factor magnitude from resistance and net reactance.
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Energy From Power And Time Calculator
Calculate electrical energy in watt-hours and kilowatt-hours by multiplying constant power by elapsed time.
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Energy Intensity Calculator
Calculate energy and cost intensity from annual electricity use, served floor area, and energy rate for a building-level screening view.
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Energy Cost per Device Calculator
Calculate per-device energy and cost from device watts, quantity, runtime, operating days, and energy rate, with total annual cost for the repeated load.
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Enclosure Heat Dissipation Calculator
Calculate enclosure temperature rise, internal temperature, and margin from internal heat, ambient temperature, and thermal resistance.
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Demand Charge Cost Calculator
Calculate monthly and selected-period demand charge cost from billing demand, demand rate, and billed months.
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DC Power From Voltage And Current Calculator
Calculate steady-state DC watts from entered voltage and current at the same operating point.
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