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Single conversion
To convert from Megajoule (MJ) to Watt-second (Ws), use the following formula:
Let's convert 5 Megajoule (MJ) to Watt-second (Ws).
Using the formula:
Therefore, 5 Megajoule (MJ) is equal to Watt-second (Ws).
Here are some quick reference conversions from Megajoule (MJ) to Watt-second (Ws):
| Megajoules | Watt-seconds |
|---|---|
| 0.000001 MJ | Ws |
| 0.001 MJ | Ws |
| 0.1 MJ | Ws |
| 1 MJ | Ws |
| 2 MJ | Ws |
| 3 MJ | Ws |
| 4 MJ | Ws |
| 5 MJ | Ws |
| 6 MJ | Ws |
| 7 MJ | Ws |
| 8 MJ | Ws |
| 9 MJ | Ws |
| 10 MJ | Ws |
| 20 MJ | Ws |
| 30 MJ | Ws |
| 40 MJ | Ws |
| 50 MJ | Ws |
| 100 MJ | Ws |
| 1000 MJ | Ws |
| 10000 MJ | Ws |
For all Energy converters, choose units using the From/To dropdowns above.
Ever looked at a food label outside the US or heard about the energy of a lightning bolt and seen the term 'megajoule' or 'MJ'?
What exactly is it?
In this simple guide, we'll break down what a megajoule is, how big it is, and where you'll see it used in everyday life and science.
A Megajoule (MJ) is a unit of energy in the International System of Units (SI), equal to one million Joules (106 J).
The plural form is Megajoules.
To visualize the energy in a single megajoule, it helps to use a powerful real-world comparison.
One megajoule (1 MJ) is roughly the same as the kinetic energy of a one-tonne car traveling at 160 km/h (about 100 mph).
This comparison shows just how much energy a single megajoule represents, making it a key unit for measuring large energy transfers in fields like physics and engineering.
In many countries, including Australia and New Zealand, the megajoule (MJ) and kilojoule (kJ) are the standard units on nutritional labels to measure the energy content of food, instead of Calories (kcal).
To understand these labels, it's helpful to know the conversion:
One megajoule (MJ) is equal to approximately 239 food Calories (kcal).
This makes the MJ a critical unit for international dietary and health management.
The megajoule is a common unit for quantifying large-scale energy events and outputs in science and technology.
For example:
A Watt-second (Ws) is a unit of energy in the International System of Units (SI), equal to exactly one Joule (J).
It is a fundamental measurement used to quantify energy transfer, especially in fields like physics and photography.
The relationship is simple: one Watt-second is precisely equal to one Joule.
This 1:1 equivalence means the two units are entirely interchangeable. So, if you have 100 Ws of energy, you also have 100 J of energy.
This makes it a straightforward and reliable unit for any precise energy calculation.
In photography, the Watt-second is the standard for measuring the maximum energy output of a studio strobe or electronic camera flash.
Essentially, a higher Watt-second rating means a more powerful flash.
For example, a 500 Ws strobe has more flash power than a 200 Ws unit, allowing it to produce a much brighter burst of light.
This extra power is crucial for illuminating larger scenes or overpowering ambient light, like bright sunshine.
The name "Watt-second" perfectly describes its own formula.
It is the amount of energy used when one Watt of power is applied for exactly one second.
This gives us the fundamental equation for energy transfer:
Energy (Ws) = Power (W) × Time (s)
To sum up, while the Watt-second is a universal unit of energy equivalent to a Joule, its most common practical use is in photography.
When choosing a studio strobe or camera flash, a higher Ws rating gives you more lighting power, offering greater creative control over your shots.