About this tool
The electricity bill is the kWh you use multiplied by the tariff of your distributor. Each appliance uses its power in watts times the hours it is on: an electric shower of 5,500 W used half an hour a day goes through 82.5 kWh a month, more than everything else in many homes. This calculator starts with a typical Brazilian home (shower, fridge, TV, washing machine, iron, microwave, computer, LED bulbs and Wi-Fi router) and lets you change the quantity, the watts, the hours a day and the days a month of each, switch on the air conditioner or add another appliance. Type the tariff from your bill and, when a yellow or red tariff flag applies, its surcharge per 100 kWh. It shows the cost a month, per day and per year, the kWh and a table with each appliance's share. Everything is calculated in your browser.
How to use it
- 1 Find the tariff on your bill, or divide the total in R$ by the kWh used to get it with taxes.
- 2 Type the tariff and, if a yellow or red flag applies, the surcharge per 100 kWh (green flag = 0).
- 3 Adjust each appliance: quantity, power in watts (on its label), hours a day and days a month. Quantity 0 leaves it out.
- 4 Read the cost a month and the table that shows what weighs most on the bill.
Frequently asked questions
How do I calculate the consumption of an appliance?
Multiply its power in watts by the hours it is on a day and by the days of use in the month, then divide by 1,000 to get kWh. A 100 W TV on for 5 hours a day for 30 days uses 100 × 5 × 30 ÷ 1,000 = 15 kWh. Multiply the kWh by the tariff to get the cost.
Where do I find the power of an appliance?
On the label or plate on the appliance, in the manual or on the Procel/Inmetro energy label, which for fridges and air conditioners already gives the kWh a month. For appliances that switch on and off by themselves, like the fridge, use an average power: the starting value assumes the motor runs about 8 hours a day.
What is the tariff flag (bandeira tarifária)?
A surcharge ANEEL applies when electricity costs more to generate, usually in dry months: green adds nothing, yellow and red add a fixed amount per 100 kWh. The bill shows which flag applied; type its amount per 100 kWh in the field to include it.
Why is my bill different from the result?
The bill also has the street-lighting fee set by the city, the minimum (availability) charge, taxes that vary by state and the days of the reading period. Use the tariff with taxes (total ÷ kWh) to get close, and remember the real use of each appliance changes from month to month.
Is my data sent anywhere?
No. The calculation runs in your browser and nothing you type is sent or stored.
Guide
Embed this tool
Add this free tool to your own website — copy the code below. It stays up to date automatically.
Tools for your site →