Calculadora de Conversor de Watt
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
W ↔ kW ↔ hp ↔ BTU/h
About this calculator
The Watt Converter Calculator allows you to convert power values between four common units: watt (W), kilowatt (kW), horsepower (hp), and BTU per hour (BTU/h). Simply enter the number and select the source unit to instantly get equivalents in the other units. This tool is ideal for engineers, technicians, and students who need to compare equipment specifications or solve physics and engineering problems.
The operation is straightforward: the calculator uses fixed conversion factors. For example, 1 kW equals 1000 W, 1 hp equals approximately 745.7 W, and 1 BTU/h equals about 0.293 W. When you enter a value, the system applies these relationships to calculate results in the other units. The interface is intuitive and provides immediate feedback, making it easy to use even for those unfamiliar with the formulas.
This calculator is useful in various practical situations. When buying an air conditioner, you can convert BTU/h to watts to compare with available electrical power. In motor projects, converting hp to kW helps correctly size the power supply. It is also useful in energy efficiency calculations, where different units are used in different contexts.
Cautions: remember that conversions are approximate, especially for hp (there are variations like mechanical hp and metric hp; here we use mechanical hp, where 1 hp = 745.7 W). For BTU/h, the conversion uses the standard value of 1 BTU/h = 0.293071 W. Always verify that the source unit is correct before using the result in critical calculations.
Frequently asked questions
How do I convert watts to horsepower?
Divide the value in watts by 745.7. For example, 1000 W / 745.7 ≈ 1.34 hp.
What is the difference between mechanical hp and metric hp?
Mechanical hp (used in the calculator) equals 745.7 W, while metric hp (cv) equals 735.5 W. The difference is about 1.4%.
Can I use this calculator to convert BTU/h to kW?
Yes. Simply enter the value in BTU/h and select BTU/h as the source unit; the result in kW will be displayed automatically.
Does the calculator apply rounding?
Yes, results are rounded to two decimal places for readability. For precise calculations, use the exact values.
What is the most common unit for power in household appliances?
In Brazil, watts (W) and kilowatts (kW) are most common for appliances, while BTU/h is used for air conditioners and hp for motors.