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Converters

Electrical conversion calculators

Watts, amps, kVA, Ohm's law, voltage drop, battery capacity: the fast, accurate conversions. Every one also tells you the NEC wire and breaker the result needs, not just the number.

converters
34
categories
4
wire + breaker shown
NEC
Watts ↔ amps converter

Space Heater

1,500 W÷120 V=12.5 A

Amps = watts ÷ volts (single-phase, resistive load)

0114 converters

Power & Current

Watts ↔ Amps

Convert watts to amps (or amps to watts) for DC, single-phase, and three-phase, plus the NEC wire and breaker the result needs.

Open converter

kW ↔ Amps

Convert kilowatts to amps (or amps to kW) for DC, single-phase, and three-phase circuits, with the matching NEC wire and breaker size.

Open converter

Volts ↔ Watts

Convert volts to watts (or watts to volts) using the current (watts = volts × amps) for DC, single-phase, and three-phase, with the NEC wire and breaker.

Open converter

Watts ↔ kW

Convert watts to kilowatts and back. 1 kW = 1,000 W. Enter watts or kilowatts to see the other instantly.

Open converter

MW ↔ kW

Convert megawatts to kilowatts and watts (or back): a power-unit conversion. 1 MW = 1,000 kW = 1,000,000 W. For utility, solar, and generator capacity.

Open converter

HP ↔ kW

Convert horsepower to kilowatts (or kW to HP) for motors, pumps, and generators, with the estimated current draw and the NEC wire and breaker it points to.

Open converter

kVA → Amps

Convert kVA to amps (full-load current) for single- and three-phase systems, and the breaker and wire to feed it. For transformers and generators.

Open converter

kVA ↔ kW

Convert kVA to kW (or kW to kVA) using the power factor: apparent vs real power for generators, transformers, and UPS systems.

Open converter

HP ↔ Amps

Convert horsepower to amps (or amps to HP) for motors (by voltage, efficiency, and power factor) with the NEC wire and breaker the current needs.

Open converter

kW ↔ HP

Convert kilowatts to horsepower (mechanical, electrical, and metric HP side by side), plus the motor input kW and full-load amps at 120V, 240V, and 480V.

Open converter

Amps ↔ kW

Convert amps to kilowatts for DC, single-phase, and three-phase circuits with power factor, plus the NEC breaker and copper wire the current needs.

Open converter

Volts ↔ Amps

Convert volts to amps using resistance (Ohm's law) or power (watts), for DC and AC, with the NEC breaker and wire size for the resulting current.

Open converter

Watts ↔ Volts

Convert watts to volts using current (V = W ÷ A) or resistance (V = √(W × R)), for DC, single-phase, and three-phase, with the nearest standard system voltage.

Open converter

Kilowatts ↔ Watts

Convert kilowatts to watts (1 kW = 1,000 W) across the full SI ladder (milliwatts to gigawatts), with real appliance and equipment examples at each scale.

Open converter

024 converters

Circuit Design

Ohm's Law

Solve volts, amps, ohms, and watts from any two values using the full Ohm's law power wheel, with the wire ampacity for the resulting current.

Open converter

Voltage Drop

Calculate voltage drop and percentage over a wire run, and get the smallest wire gauge that keeps you under the NEC 3% recommendation.

Open converter

Amps ↔ kVA

Convert amps to kVA for single-phase and three-phase, plus the next standard transformer size up and the real kW the load delivers at your power factor.

Open converter

kW ↔ kVA

Convert kW to kVA at any power factor, with the next standard generator and transformer size up, the rating you actually have to buy for the load.

Open converter

032 converters

Battery

Ah ↔ kWh

Convert battery amp-hours to kWh (and back), with usable capacity after depth-of-discharge and efficiency, plus runtime for a given load.

Open converter

mAh ↔ Wh

Convert mAh to Wh (or Wh to mAh) for batteries and power banks using the voltage: Wh = mAh × V ÷ 1,000. Check airline limits in watt-hours.

Open converter

0414 converters

Energy & HVAC

Watts ↔ kWh

Convert watts to kilowatt-hours (or kWh to watts) by run time: turn an appliance's wattage into the energy it uses, the unit your utility bills.

Open converter

BTU ↔ kW

Convert BTU/hr to kW, watts, and refrigeration tons (or kW back to BTU) for heat pumps, AC, and furnaces: compare heating and cooling output across units.

Open converter

MWh ↔ kWh

Convert megawatt-hours to kilowatt-hours and back, plus watt-hours and gigawatt-hours. 1 MWh = 1,000 kWh. Enter any energy unit to see the rest.

Open converter

kWh ↔ MWh

Convert kilowatt-hours to megawatt-hours (MWh = kWh ÷ 1,000), plus watt-hours and gigawatt-hours. For utility data, solar production, and grid-scale figures.

Open converter

BTU ↔ kWh

Convert BTU to kWh and back, plus therms and MMBtu. Energy-unit conversion (1 kWh = 3,412 BTU) for comparing gas and electric energy use.

Open converter

kW ↔ kWh

Convert kilowatts to kilowatt-hours (or kWh back to kW) by run time: turn a device's power in kW into the energy it uses. kWh = kW × hours.

Open converter

Watts ↔ Joules

Convert watts to joules (power × time) and convert between joules, kilojoules, watt-hours, kWh, and calories. 1 watt for 1 second = 1 joule.

Open converter

Therms ↔ kWh

Convert therms of natural gas to kWh (or back), plus BTU, ccf, and MMBtu. 1 therm = 100,000 BTU ≈ 29.3 kWh. Compare gas and electric energy.

Open converter

kWh ↔ Watts

Convert kWh to watts by dividing energy over the hours it ran, the reverse meter-reading math, with the appliance that matches the resulting draw.

Open converter

kWh ↔ kW

Convert kWh to kW over a run time, and see why utilities bill energy (kWh) and demand (kW) separately, including what a demand charge costs.

Open converter

kW ↔ BTU/h

Convert kW to BTU per hour (1 kW = 3,412 BTU/h) and to tons of cooling, with the HVAC equipment size that matches the result.

Open converter

kWh ↔ BTU

Convert kWh to BTU (1 kWh = 3,412.14 BTU) plus therms, ccf, and MMBtu, and compare what the same energy costs as electricity versus natural gas.

Open converter

kWh ↔ Therms

Convert kWh to therms of natural gas (1 therm = 29.3 kWh) and compare the cost of the same heat delivered by gas, resistance electric, or a heat pump.

Open converter

Joules ↔ Watts

Convert joules to watts by dividing energy over time (W = J ÷ s), with seconds, minutes, or hours, plus the kWh, BTU, and calorie equivalents.

Open converter

Got the amps? Size the circuit.

Turn a converted load into the wire, breaker and panel capacity it needs.

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