Physics

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Watt Converter.

Convert power using explicitly selected SI, mechanical horsepower, metric horsepower, or Btu/h units.

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Power

From

watts

0.00000000

converted

0.00000000

Results update automatically as you type.

Convert power using explicitly selected SI, mechanical horsepower, metric horsepower, or Btu/h units.

Use Cases

Compare appliance power ratings

When shopping for appliances or equipment, power ratings may be given in different units. Use this converter to compare them on a common scale.

Example: Convert a 1.5 kW heater to Btu/h to compare with a 5,000 Btu/h air conditioner.

Understand vehicle engine power

Car and motorcycle specifications often list power in horsepower (mechanical or metric). Convert to kilowatts to understand the power in SI units.

Example: Convert 150 mechanical hp to kW to see the metric equivalent.

Frequently Asked Questions

How do I convert watts to horsepower?: Select W as the 'From' unit and mechanical hp or metric hp as the 'To' unit, then enter the power value. The converter will automatically calculate the equivalent horsepower.
What is the difference between mechanical and metric horsepower?: Mechanical horsepower (hp) is defined as 745.7 watts, while metric horsepower (PS) is defined as 735.5 watts. This converter supports both, so you can choose the correct one for your application.
Can I convert Btu/h to watts?: Yes, select Btu/h as the 'From' unit and W as the 'To' unit. The converter will use the standard conversion factor of 1 Btu/h = 0.29307107 watts.

Tips & Common Mistakes

Tips

Always double-check the unit you select for 'From' and 'To' to avoid errors.
For precise engineering calculations, use the exact conversion factors provided by the converter.
Remember that mechanical horsepower and metric horsepower are different; choose the one that matches your context.
If you're converting large values, consider using kilowatts or megawatts to keep numbers manageable.

Common Mistakes to Avoid

Confusing mechanical horsepower with metric horsepower, leading to incorrect conversions.
Forgetting to select the correct 'From' and 'To' units, resulting in reversed conversions.
Assuming Btu/h is the same as BTU (energy) without the per-hour time component.

Last updated: August 13, 2026

Use Cases

Compare appliance power ratings

When shopping for appliances or equipment, power ratings may be given in different units. Use this converter to compare them on a common scale.

Example: Convert a 1.5 kW heater to Btu/h to compare with a 5,000 Btu/h air conditioner.

Understand vehicle engine power

Car and motorcycle specifications often list power in horsepower (mechanical or metric). Convert to kilowatts to understand the power in SI units.

Example: Convert 150 mechanical hp to kW to see the metric equivalent.

Frequently Asked Questions

How do I convert watts to horsepower?

Select W as the 'From' unit and mechanical hp or metric hp as the 'To' unit, then enter the power value. The converter will automatically calculate the equivalent horsepower.

What is the difference between mechanical and metric horsepower?

Mechanical horsepower (hp) is defined as 745.7 watts, while metric horsepower (PS) is defined as 735.5 watts. This converter supports both, so you can choose the correct one for your application.

Can I convert Btu/h to watts?

Yes, select Btu/h as the 'From' unit and W as the 'To' unit. The converter will use the standard conversion factor of 1 Btu/h = 0.29307107 watts.

Tips & Common Mistakes

Tips

Always double-check the unit you select for 'From' and 'To' to avoid errors.
For precise engineering calculations, use the exact conversion factors provided by the converter.
Remember that mechanical horsepower and metric horsepower are different; choose the one that matches your context.
If you're converting large values, consider using kilowatts or megawatts to keep numbers manageable.

Common Mistakes to Avoid

Confusing mechanical horsepower with metric horsepower, leading to incorrect conversions.
Forgetting to select the correct 'From' and 'To' units, resulting in reversed conversions.
Assuming Btu/h is the same as BTU (energy) without the per-hour time component.

Use Cases

Compare appliance power ratings

When shopping for appliances or equipment, power ratings may be given in different units. Use this converter to compare them on a common scale.

Example: Convert a 1.5 kW heater to Btu/h to compare with a 5,000 Btu/h air conditioner.

Understand vehicle engine power

Car and motorcycle specifications often list power in horsepower (mechanical or metric). Convert to kilowatts to understand the power in SI units.

Example: Convert 150 mechanical hp to kW to see the metric equivalent.

Frequently Asked Questions

How do I convert watts to horsepower?

Select W as the 'From' unit and mechanical hp or metric hp as the 'To' unit, then enter the power value. The converter will automatically calculate the equivalent horsepower.

What is the difference between mechanical and metric horsepower?

Mechanical horsepower (hp) is defined as 745.7 watts, while metric horsepower (PS) is defined as 735.5 watts. This converter supports both, so you can choose the correct one for your application.

Can I convert Btu/h to watts?

Yes, select Btu/h as the 'From' unit and W as the 'To' unit. The converter will use the standard conversion factor of 1 Btu/h = 0.29307107 watts.

Tips & Common Mistakes

Tips

Always double-check the unit you select for 'From' and 'To' to avoid errors.
For precise engineering calculations, use the exact conversion factors provided by the converter.
Remember that mechanical horsepower and metric horsepower are different; choose the one that matches your context.
If you're converting large values, consider using kilowatts or megawatts to keep numbers manageable.

Common Mistakes to Avoid

Confusing mechanical horsepower with metric horsepower, leading to incorrect conversions.
Forgetting to select the correct 'From' and 'To' units, resulting in reversed conversions.
Assuming Btu/h is the same as BTU (energy) without the per-hour time component.