Smarter Home Gadgets/Tools

Smart home tools

Three calculators built on the same data as our guides. They run entirely in your browser: nothing you type is sent anywhere. The code is open source under the MIT licence.

01

Standby cost calculator

What your devices draw while doing nothing, per year. Presets are our test-home measurements; change any value.

Per year——

Formula: watts × 24 h × 365 days ÷ 1000 × price per kWh.

02

Zigbee channel picker

Tick the 2.4 GHz Wi-Fi channels in use around you, including your neighbours' if you know them.

Wi-Fi channels in use
Zigbee channels

    A Zigbee channel is counted as overlapping when its centre falls inside the 20 MHz block of a Wi-Fi channel you ticked. 15, 20 and 25 are preferred because they clear the usual 1, 6 and 11 and are widely supported.

    03

    Off-peak savings calculator

    What moving a load to the cheap tariff saves in a year. The preset is the shift that produced half of our test home's savings.

    Example prices, not a real tariff: replace them with the two prices on your own bill.

    Saved per year—

    Formula: kWh moved × (peak price − off-peak price).

    Open source

    All three tools are a single script, published under the MIT licence: tools.js (MIT).