Appliance Running Cost Calculator
Pick an appliance from the list and get its running cost immediately. Or enter custom wattage and hours to find out what any device actually costs per month.
Last updated: May 2026
Select an appliance or enter wattage and hours to calculate running cost.
Monthly cost = (W / 1000) * hours/day * 30.44 * tariff
Why your fridge might be your biggest electricity cost
High-wattage appliances get the attention, but always-on devices quietly accumulate the largest bills. A refrigerator rated at 120 W sounds modest compared to a 2,000 W kettle. But the fridge runs 24 hours a day, every day. At €0.32/kWh, that's around €28 per month. The kettle, used for 6 minutes twice a day, costs under €1.
The preset wattage values here are typical measured draw values, not nameplate maximums. A washing machine rated at 2,200 W on its label may actually draw 2,000 W during a 60°C wash. For precise figures, use a smart plug with energy monitoring to measure your specific appliance.
Appliance running cost reference
Monthly cost at €0.32/kWh, 7 days/week, at the typical daily hours shown.
| Appliance | Typical wattage | Daily use | Monthly cost |
|---|---|---|---|
| Refrigerator A++ | 120 W | 24 h | €28.00 |
| Refrigerator (older) | 200 W | 24 h | €46.27 |
| Gaming PC (high-end) | 500 W | 4 h | €19.48 |
| NAS / home server | 30 W | 24 h | €7.00 |
| LED TV 55-inch | 100 W | 5 h | €4.87 |
| Air fryer (2L) | 1500 W | 0.5 h | €7.31 |
| Laptop | 45 W | 8 h | €3.50 |
| Washing machine (60°C) | 2000 W | 1 h | €19.48 |
| EV charger (7.4 kW) | 7400 W | 2 h | €144.25 |
| Electric kettle | 2000 W | 0.1 h | €1.95 |
From an appliance nameplate to its yearly running cost
Before you get to this calculator, a circuit has already been designed behind the appliance: the wire gauge calculator sized the conductor to carry the load, the voltage drop calculator confirmed the run stays within the 3% IEC limit, the fuse calculator chose protection rated to the cable, and the conduit fill calculator checked the cables fit inside the conduit. On the supply side, the power supply calculator sized the source and, for reactive loads, the power factor calculator corrected watts to the VA a generator or UPS must deliver. You are here: what an appliance costs to run. Take the nameplate wattage, enter your daily hours and tariff, and this calculator turns those into a daily, monthly and yearly figure. From here the natural next step is the electricity cost calculator, which adds multiple appliances into a single household total. One thing that consistently surprises people when they run these numbers: the loads worth chasing are the ones that run for hours, not the ones with big wattage figures. An always-on standby device can outcost a high-wattage appliance you use for minutes.
Frequently Asked Questions
Why is my fridge the biggest electricity cost even though it's low wattage?
Running time is the multiplier that matters most. A refrigerator rated at 120 W draws power continuously: 24 hours a day, 365 days a year. That adds up to 1,051 kWh per year. Compare this to a 2,000 W kettle used for 6 minutes twice a day: it consumes just 146 kWh per year. The fridge uses 7 times more energy despite drawing far less power at any given moment. Always-on devices (fridges, NAS servers, routers, set-top boxes) are where the long-run electricity cost concentrates.
My gaming PC has a 650 W PSU. Does it really draw 650 W?
No. The PSU wattage is the maximum it can supply, not the actual draw. A system with a 650 W PSU typically draws 80-150 W at the Windows desktop, 300-500 W while gaming under heavy GPU load, and around 250-350 W during CPU-intensive tasks. The actual draw depends on the GPU and CPU workload, not the PSU rating. If you want to know real consumption, plug a smart energy monitor between the wall socket and the power strip; it will show live wattage and cumulative kWh.
How do I work out which appliances to target first when trying to cut my bill?
Sort by annual energy, not by peak wattage. Multiply each appliance's wattage by its daily hours of use to get daily kWh, then multiply by 365 to get a yearly figure. Devices with a high wattage but short daily runtime (kettle, toaster, microwave) often rank lower than devices with a modest wattage that run continuously or for many hours (fridge, NAS server, always-on TV box). Once you have a ranked list, the top entries are worth targeting first: replacing an older fridge with an A+++ model, switching halogen bulbs to LED, and cutting tumble-dryer cycles are typically the three moves with the largest return. Use the calculator above on each appliance in turn to build that ranked list before deciding where to act.
How do I measure my actual appliance wattage?
The most practical method for home use is a smart plug with energy monitoring, such as the TP-Link Kasa EP25 or Shelly Plug S, which shows live wattage and tracks cumulative kWh. Plug it in between the wall and the appliance. For permanently wired appliances (cooker, oven, EV charger) or whole-circuit measurement, a clamp meter clamped around the live wire will read current draw, and multiplying by voltage gives watts. Your smart meter's in-home display also shows total household draw in real time; switch appliances on and off one at a time to see their individual impact.
Methodology and sources
This tool estimates what an appliance costs to run by converting its power draw into energy used over time, then multiplying by your electricity tariff. It is standard energy arithmetic, not a measured reading of your specific device.
- Method: energy per day in kWh = (watts / 1000) × hours per day. Cost per day = kWh per day × tariff. Monthly cost = daily cost × 30.44 (average days per month, 365.25 / 12); yearly cost = daily cost × 365.25.
- Standards and sources: standard physics and arithmetic (power × time = energy, billed per kWh). No industry standard governs the calculation. The preset wattages are typical measured-draw values for common appliances, not nameplate maximums, and tariffs are illustrative country averages.
- Assumptions and limits: assumes a constant power draw for the hours entered and a flat per-kWh tariff. Real appliances cycle on and off (a fridge compressor does not run continuously), motors draw a surge at start-up, and many tariffs are time-of-use or tiered. For an exact figure, measure your own device with an energy-monitoring smart plug.
Reviewed and maintained by Rick Oosterling, who builds and wires 12 V, solar and EV systems hands-on. Last reviewed: June 2026. Estimates only; tariffs, prices and usage vary, so treat the figures as a planning guide rather than a billed amount.
Next step in this workflow
Now add this appliance to your total household running cost.