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Convert watt-hours to joules

1 Wh=3,600J

Use the converter below to change any watt-hours value into joules instantly — with formula, conversion table, and real-world examples.

3,600

Conversion formula

Forward
joules = watt-hours × 3,600
Reverse
watt-hours = joules × 0.0002778

Example: 10 Wh × 3,600 = 36,000 J.

About both units

From

Watt-Hour

Wh

The watt-hour equals 3600 joules — 1 W delivered for 1 hour. Used for phone, laptop and small-battery capacities. A typical smartphone battery is 10–20 Wh; a laptop is 50–100 Wh.

Real-world: iPhone battery: 12 Wh. MacBook Pro: 70 Wh. Power bank: 20 Wh–100 Wh. Airplane carry-on limit: usually 100 Wh.
Read full watt-hour reference →
To

Joule

J

The joule is the SI unit of energy, work and heat. Defined as one newton-metre or one watt-second. Named after James Prescott Joule who demonstrated the mechanical equivalent of heat. Lifting a 100 g apple 1 metre requires about 1 J.

Real-world: Lifting a 100 g apple 1 m: ≈ 1 J. 100 kcal snack: 418,400 J. Hand grenade: ~650 kJ.
Read full joule reference →

Watt-Hour to Joule conversion table

Common watt-hours to joules values for quick reference.

Watt-Hour (Wh)Joule (J)
1 Wh3,600 J
10 Wh36,000 J
100 Wh360,000 J
500 Wh1,800,000 J
1,000 Wh3,600,000 J
5,000 Wh18,000,000 J
10,000 Wh36,000,000 J
50,000 Wh180,000,000 J
100,000 Wh360,000,000 J
500,000 Wh1,800,000,000 J

Tips & common mistakes

Quick tips

  • 1 Wh = 3600 J = 0.001 kWh.
  • Battery mAh × V = Wh. A 3000 mAh phone battery at 3.7 V = 11.1 Wh.
  • Airline limits lithium batteries to 100 Wh for carry-on.

Avoid these

  • Confusing mAh with Wh — need voltage to convert.
  • Using Wh when kWh is more appropriate for large batteries.
  • Forgetting the voltage in battery capacity calculations.

Frequently asked questions

How many joules in a watt-hour?
One watt-hour equals 3,600 joules.
How do I convert watt-hours to joules?
Multiply the watt-hour value by 3,600 to get the equivalent in joules.
What is 100 watt-hours in joules?
100 watt-hours equals 360,000 joules.
Is a watt-hour bigger than a joule?
Yes. 1 watt-hour equals 3,600 joules, so one watt-hour is larger.
How to convert watt-hours to joules without a calculator?
Multiply by 3,600 for a quick estimate; use a calculator for precise results.

Related energy conversions

📊 See full comparison matrix →

More from Watt-Hour

Wh → kJ
1 = 3.6 kJ
Wh → MJ
1 = 0.0036 MJ
Wh → kWh
1 = 0.001 kWh
Wh → cal
1 = 860.421 cal
Wh → kcal
1 = 0.8604 kcal
Wh → BTU
1 = 3.41214 BTU
Wh → eV
1 = 2.2469e22 eV
Wh → thm
1 = 3.4121e-5 thm

More to Joule

kJ → J
1 = 1,000 J
MJ → J
1 = 1,000,000 J
kWh → J
1 = 3,600,000 J
cal → J
1 = 4.184 J
kcal → J
1 = 4,184 J
BTU → J
1 = 1,055.06 J
eV → J
1 = 1.6022e-19 J
thm → J
1 = 105,505,585.3 J

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