Martin Lewis has revealed how to calculate the cost of each household appliance.
It comes after the new Energy Price Guarantee came into effect from October 1 - meaning bills are "frozen" at £2,500 for the average household for the next two years.
This isn't a total cap on your bill though. The new Government scheme instead caps the unit rates and standing charges you pay for gas and electricity.
This means if your energy usage is high, you'll end up paying more.
Families across the country will be looking to manage their budgets this winter as the new cap comes into force.
The MoneySavingExpert founder took to Twitter to share his tips on calculating the cost of toasters, washing machines, microwaves and more.
In a short step-by-step tweet, he revealed that in order to find out how much an appliance is costing you, you must first find its wattage.
Then, you should know that 1000W is a Kilowatt (kW), and you pay roughly 34p per kW per hour.
He added: "So 100W (a tenth of a kW) appliance on for two hours is 3.4p an hour x 2 = 6.8p"
The money expert said his calculation was a "rule of thumb" to give people an indication of running costs, rather than an exact cost.
He also added that the calculation is most useful when talking about how much will it cost to switch on a specific appliance, rather than appliances that are constantly on.
In more energy-saving news, a fan of Martin Lewis explained how they cut their energy bill by £1,300.
The MoneySavingExpert reader, known only as Mavis, said she had locked into a two-year fixed deal that would have cost her £3,600.
Her bill was then reduced when the new Energy Price Guarantee came into force.
She said: "We locked in to a two-year fix at the end of August, which would have cost £3,600 a year. After your talks with suppliers, we waited to see what would happen.
“We've now been told we will be transferred to the price-capped tariff without any penalty. New annual cost: £2,300. Thank you."
If you fixed into an energy deal that is higher than the Energy Price Guarantee, then you will see the same unit rate reduction applied to your bill.
The discount is 4p/kWh for gas, and 17p/kWh for electricity.
If you'll pay less than the Energy Price Guarantee, then the discount won't be applied to your fix - but you'll still enjoy the lower rate.
If you picked a medium-level fix, then your bill should be lowered to match the new Energy Price Guarantee.
Current unit rates for direct debit customers on the Energy Price Guarantee coming in at 10.3p/kWh for gas, and 34p/kWh for electricity.
This is the "floor" unit rate price that you will get, if a discount is applied.
