What does an irrigation controller cost to run?

Run the numbers on your own use

Change any of these and the figures update. The defaults are the typical case described above; your rate is the input that moves the answer most.

Why this is lower than the number you will see elsewhere

Almost every published answer to this question multiplies the rating on the label by the hours the appliance is switched on. For an irrigation controller that gives 35 kWh a year, or $6.43.

Continuous. The transformer and the electronics are live all year, including through winter when the system is drained.

The arithmetic, step by step

Nothing here is hidden, so you can check it or change it. Working in the order the formula runs:

1. 4 W — what it draws while it is actually drawing. This is the rating on the plate.
2. × 100% — the share of its in-service time it is really pulling that. Continuous. The transformer and the electronics are live all year, including through winter when the system is drained.
   That gives 4 W averaged across the hours it is on.
3. × 24 hours a day × 365 days — A residential controller left connected year round.
   4 × 24 × 365 ÷ 1,000 = 35 kWh a year.
4. × 18.34¢ — the US average residential rate for June 2026.
   35 kWh × 18.34¢ = $6.43 a year.

Change any assumption in the calculator above and every figure on this page moves with it. The two that matter most are your rate, which varies 4× across the country, and the hours — the duty cycle is a property of the appliance, but the hours are a property of you.

How sensitive is that number?

A single figure invites more confidence than it deserves. Here is the same appliance under assumptions either side of the default, so you can see how much of the answer is the appliance and how much is the guess about how you use it.

Everything else held at the default. The spread here is the honest error bar on the headline figure.

What it costs per hour, day and month

At 18.34¢ per kWh, the US residential average for June 2026.

The thing worth knowing

Trivial on its own — a few dollars a year — and included precisely because it is the kind of thing that makes an always-on total add up. A house has a dozen of these small permanent loads, and the total is what matters rather than any one of them.

What it costs in your state

The appliance is the same everywhere; the rate is not. Running this irrigation controller costs $18 a year in Hawaii and $4.59 in Nevada — a difference of 4×.

Cost of running one irrigation controller for a year, by state. Residential average price, EIA June 2026.

Other tools, hobbies and outdoors costs

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• Oxygen concentrator

  $375 a year

  A stationary home unit at a moderate flow rate, sixteen hours a day.

• Pottery kiln

  $190 a year

  A medium studio kiln fired roughly twice a month to cone 6.

• Electric fireplace

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  Evenings through winter with the heater on.

• Home server or NAS

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• Radon mitigation fan

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  A typical sub-slab depressurisation fan running as installed.

Questions

Source: U.S. Energy Information Administration, Electric Power Monthly, Table 5.6.A, June 2026. U.S. Government work, public domain.

How every figure on this page is computed · Where the data comes from