Energy cost calculator: what cooling really costs to run
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This energy cost calculator turns any device’s wattage into money: per day, per month, per cooling season — with editable tariff presets for the US, UK, Germany, France and Spain, and a one-click 45 W vs 340 W vs 1,200 W face-off.
Formula: kWh = W × h ÷ 1,000; cost = kWh × rate. Presets are recent national ballparks for orientation — verify against your own bill; season = 4 months at your daily use.
The three-line math
Electricity pricing is mercifully simple: watts × hours ÷ 1,000 gives kWh; kWh × your tariff gives money. Everything else is finding the honest wattage — which, in this market, brands often withhold. Where a spec is missing, our reviews say so and the power calculator derives watts from volts and amps on the label.
Why the wattage gap is the story
A 45 W evaporative cooler, a 340 W personal compressor and a 1,200 W conventional portable are three different bills for three different jobs. The comparison button prices all three at your tariff and hours — the honest context behind every “pennies a day” ad, including the ones for products we review. Full physics: evaporative vs compressor.
Frequently asked questions
How does the energy cost calculator work?
Watts × hours ÷ 1,000 = kWh, then kWh × your tariff. This energy cost calculator ships editable country presets (recent national ballparks for the US, UK, Germany, France and Spain) — always overwrite with the rate on your own bill for exact figures.
What does a 45 W cooler cost per month?
At 45 W for 10 h/day, that is 0.45 kWh daily — roughly 13.5 kWh a month. At a $0.17/kWh US-average tariff, about $2.30. The comparison button below runs this against 340 W and 1,200 W devices live.
Why do you say “ballpark” tariffs?
Household rates move with markets and caps, and vary by region and plan. The presets orient you; your bill decides. Edit the rate field freely — the math updates instantly.
Does heating mode change the math?
Only the wattage. Electric heat in 2-in-1 devices typically draws hundreds of watts versus tens for evaporative cooling — enter the heat-mode wattage and the same formula prices your winter.
Is standby power worth counting?
For this category, rarely — a watt or two. For always-plugged compressor units with displays, add ~1–2 W × 24 h if you want the pedantic total.