Free. No signup, no email, and they keep working when the signal doesn’t.
Heat input from your own meter readings.
Measure, tap the outside walls, get the watts.
Add it to your home screen and both calculators work with no signal at all. How.
Two taps put the toolkit on your home screen, where it opens like an app.
Open it from your home screen and it works with no signal — in a plant room, a basement, anywhere. Every calculation runs on your phone — your readings never leave it.
Or, by hand:
Built by a practising Gas Safe registered engineer, working in North London since 2008 — because he needed these on jobs and there was nothing decent on a phone.
These are calculation aids. They compute figures from your own readings and measurements. They do not assess, approve or determine the safety of any appliance or installation — the competent person does.
These are built by one engineer and they are not finished. If a number looks wrong, say so — that is the most useful message you can send.