Calculadora de Consumo de Energia do Computador
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
kWh = W × h × 30 / 1000
About this calculator
The Computer Energy Consumption Calculator estimates the monthly electricity usage of your equipment. Simply enter the power in watts (W) of the computer, how many hours per day it is on, and the electricity tariff (R$/kWh). The calculation returns the consumption in kWh and the estimated monthly cost, considering 30 days of use.
The operation is straightforward: the formula used is kWh = (W × hours per day × 30) / 1000. In words, multiply the power in watts by the number of daily usage hours and by the days in the month (30), then divide by 1000 to convert to kilowatt-hours. Then multiply the result by the tariff to obtain the cost.
Use this calculator when you want to understand the impact of your computer on your electricity bill, whether for a desktop PC, notebook, or server. It is useful for home office workers, gamers who spend many hours playing, or professionals who keep machines running for long periods. It also helps compare different hardware configurations.
Cautions: the power entered should be the typical usage consumption, not the power supply rating. Monitors and peripherals also consume energy, but this calculator considers only the computer. The tariff should include taxes and tariff flags for greater accuracy. Remember that actual consumption may vary depending on workload.
Frequently asked questions
What is the difference between power supply rating and actual consumption?
The power supply rating is the maximum capacity, but actual consumption depends on components and usage. Use a meter or average values for your hardware.
How do I know the power in watts of my computer?
You can check the power supply manual or use software like HWMonitor. For laptops, check the power adapter.
Does the calculator consider monitors and peripherals?
No, it only calculates the computer. To include monitors, add their power separately.
What if my computer is on 24 hours?
Simply enter 24 hours per day. The calculation will consider 30 days, resulting in continuous monthly consumption.
How do I get the correct electricity tariff?
Check your electricity bill: the kWh value already includes taxes and flags. If unknown, use the average for your region (e.g., R$ 0.70).