Dynamic Electricity Price Calculator
See what it costs to run each appliance at peak, standard and off-peak rates — and how much you save by shifting to cheaper hours.
Quick Start
Tip: If you only have one flat tariff rate, enter it in all three fields to see the baseline cost — then adjust the off-peak rate down to see what a time-of-use switch would save you.
Your Tariff Rates
Check your electricity bill or supplier website for your exact rates and time windows. Rates above are typical European examples.
Appliances to Shift
Add appliances you could run at a different time. The calculator shows your current cost vs off-peak cost.
Results
Add appliances and click Calculate to see your savings.
Based on rated wattage and your entered tariff rates. Actual savings depend on your supplier's specific time windows and rates.
Best appliances to shift to off-peak
Time-of-use tariffs explained
What is a time-of-use electricity tariff? +
A time-of-use (TOU) tariff charges different prices per kWh depending on the time of day. Peak hours cost more because demand on the grid is highest. Off-peak hours cost less because the grid is underused. Shifting large loads to cheap hours reduces your bill without reducing comfort.
When are peak hours? +
Peak hours are typically 4–9 pm on weekdays when most people are home cooking, showering and watching TV. Off-peak is usually 11 pm to 7 am. The exact windows vary by supplier and country. In some markets peak rates can be double or triple the off-peak rate.
Is a time-of-use tariff right for me? +
TOU tariffs work best if you can shift major loads (washing machine, dishwasher, EV charging) outside peak hours. If your usage is fixed throughout the day — or you work from home all day running appliances constantly — the savings may be smaller. Use this calculator to check whether the switch would be worth it for your actual usage pattern.
How much can I realistically save? +
Savings depend on your tariff spread and which appliances you shift. Typical households save 10–25% on the shifted appliances, not the whole bill. The biggest gains come from EV charging, tumble dryers and dishwashers. Using a delayed start timer on your washing machine and dishwasher costs nothing and takes 30 seconds.
How dynamic electricity pricing works
Peak, standard and off-peak explained
Most households pay a single flat rate per kWh regardless of when they use electricity. Time-of-use tariffs split this into two or three price bands. The price difference between peak and off-peak can range from 10% to over 100% depending on the supplier and country.
The formula
Cost per run = (Watts ÷ 1000) × hours per run × price per kWh. To get monthly cost, multiply by the number of runs per week × 4.33 (average weeks per month).
What tariffs exist globally
In the UK, Octopus Go and Economy 7 are popular TOU tariffs. In the US, most utilities offer TOU rates at request. In Australia, peak/off-peak split tariffs are standard in many states. In Scandinavia, spot pricing (price changes every hour) is common. The calculator works with any two or three-zone structure.