Convert power (watts) to energy (joules) instantly with our free calculator. Perfect for electrical engineers, students, and professionals working with energy calculations.
Power × Time = Energy
Enter power in watts and time to calculate energy in joules
Where time is converted to seconds
Learn the relationship between power, time, and energy
A 60W light bulb running for 1 hour:
A 1,000W microwave running for 2 minutes:
A 50kW electric car charger for 30 minutes:
Quick reference for typical power ratings and their energy consumption over time
| Device/Application | Power (Watts) | 1 Second | 1 Minute | 1 Hour |
|---|---|---|---|---|
| LED Light Bulb | 10W | 10J | 600J | 36,000J |
| Laptop Computer | 65W | 65J | 3,900J | 234,000J |
| Microwave Oven | 1,000W | 1,000J | 60,000J | 3,600,000J |
| Hair Dryer | 1,500W | 1,500J | 90,000J | 5,400,000J |
| Electric Kettle | 2,000W | 2,000J | 120,000J | 7,200,000J |
| Electric Car Charger | 7,000W | 7,000J | 420,000J | 25,200,000J |
Learn the difference between power and energy units
Rate of energy transfer
Power is the rate at which energy is consumed, produced, or transferred. It tells us how fast energy is being used.
Total amount of work done
Energy is the total amount of work done or the capacity to do work. It's the cumulative effect of power over time.
Understanding energy calculations is crucial for battery selection and system design
Calculate how long a battery will power your device based on its capacity and your device's power consumption.
Determine the energy storage requirements for solar battery systems based on daily energy consumption.
Calculate backup time for UPS systems based on connected load and battery capacity.
Quick reference for converting between different energy units
Real-world scenarios where watts to joules conversion is essential
Calculate backup time for uninterruptible power supplies based on connected load and battery capacity.
Size battery banks for solar systems by calculating daily energy consumption and storage requirements.
Calculate driving range based on battery capacity and vehicle power consumption.
Calculate energy consumption for LED lighting systems and determine battery requirements for emergency lighting.
Size backup power systems for industrial equipment based on power ratings and required backup duration.
Calculate battery life for IoT devices based on transmission power and duty cycles.
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Our battery experts can help you with complex energy calculations and battery system design. Get professional consultation for your specific application requirements.