Energy converter

Kilowatt-hours to Joules Converter

Convert kilowatt-hours from your energy bill into joules, megajoules, and watt-hours.

How kWh to Joules works

A kilowatt-hour is the unit your electricity meter records: 1,000 watts sustained for one hour. Because one watt is one joule per second, a kilowatt-hour equals 1,000 × 3,600 = 3,600,000 joules.

To convert any kWh figure to joules, multiply by 3,600,000. This is useful when you want to compare a household energy figure against scientific values quoted in joules or megajoules.

Formula

1J = kWh × 3,600,000

1 kWh = 3,600 kJ = 3.6 MJ = 3,600,000 J

kWh to Joules conversion table

Reference Table7 rows

Common kilowatt-hour values converted to joules.
Kilowatt-hours↕	Joules↕	Megajoules↕
0.1 kWh	360,000 J	0.36 MJ
0.5 kWh	1,800,000 J	1.8 MJ
1 kWh	3,600,000 J	3.6 MJ
2 kWh	7,200,000 J	7.2 MJ
5 kWh	18,000,000 J	18 MJ
10 kWh	36,000,000 J	36 MJ
50 kWh	180,000,000 J	180 MJ

💡 Click any row to auto-fill the calculator aboveClick column headers to sort

FAQ: kWh to Joules

How many joules are in 1 kWh?

One kilowatt-hour equals exactly 3,600,000 joules (3.6 megajoules). It is 1,000 watts of power sustained for one hour of 3,600 seconds.

How do you convert kWh to joules?

Multiply the number of kilowatt-hours by 3,600,000. For example, 2.5 kWh × 3,600,000 = 9,000,000 joules.

Why is a kWh so many joules?

Because the joule is a very small unit. A single joule is roughly the energy to lift an apple one metre, so household-scale energy runs into the millions of joules — which is why meters use kWh instead.

Tools related to kWh to Joules

Watts to Joules ConverterThe full power × time energy calculator with three modes.Joules to kWhConvert a joule or megajoule figure into billable kilowatt-hours — divide by 3,600,000.Watts to AmpsCalculate amps from watts and volts for DC and AC circuits — I = P ÷ V.Joules to CaloriesConvert joules into calories and food Calories (kcal) — 1 cal = 4.184 J.Amps to WattsCalculate watts from amps and volts for DC and AC circuits — P = I × V.Volts to WattsConvert potential (volts) to power (watts) given the electric current — P = V × I.Wh to JoulesConvert watt-hours to joules — 1 Wh = 3,600 J.BTU to JoulesConvert heating or cooling thermal units (BTU) to joules — 1 BTU = 1,055.06 J.BTU/hr to WattsConvert heating/cooling power (BTU/hr) to electrical watts — 1 BTU/hr = 0.293071 W.mAh to JoulesConvert battery milliamp-hours (mAh) to joules given nominal voltage — E = mAh × V × 3.6.Battery Run TimeEstimate battery run time under a given load — active hours = capacity × volts × DoD ÷ load.Appliance Energy CostCalculate electricity cost for any appliance — cost = power × hours ÷ 1,000 × rate.Ohm's LawSolve Voltage, Current, Resistance, and Power from any two inputs using Ohm's Law.Voltage DropCalculate voltage drop over long electrical wire runs — V_drop = 2 × K × I × L ÷ Area.AC BTUCalculate heating/cooling BTUs needed for a room — base BTU = area × 20.Watts to HPTurn watts into horsepower — 1 mechanical hp = 745.7 W.HP to WattsTurn horsepower into watts — 1 mechanical hp = 745.7 W.Joules to WattsTurn joules of energy into watts of power — W = J ÷ seconds.Watts to OhmsFind resistance in ohms from power and voltage — R = V² ÷ P.Joules to eVTurn joules into electronvolts — 1 eV = 1.602176634×10⁻¹⁹ J.Electricity CostFind the running cost of any device — cost = (W ÷ 1000) × hours × rate.Watts to AhSize a battery from a load — Ah = (watts × hours) ÷ volts.Ah to WattsFind the load a battery supports — W = (Ah × volts) ÷ hours.Watts to VoltsFind voltage from power and current — V = P ÷ I.Joules to WhTurn joules into watt-hours — 1 Wh = 3,600 J.Joules to BTUTurn joules into BTU — 1 BTU = 1,055.06 J.Watts to Joules per SecondWatts and joules per second are the same unit — 1 W = 1 J/s.