Energy calculators

Do the maths before you spend

Quick, honest estimates for the decisions that affect your electricity bill — from a new air-conditioner to a full solar setup.

Estimate system size, generation, savings and payback for a PV system on your roof.

Work out what any appliance costs to run per hour, per month and per year.

Estimate the real cost of cooling or heating your home across a season.

Compare home charging costs with petrol or diesel, per kilometre and per month.

Check whether a home battery — with or without solar — could pay for itself.

Our approach

How our calculators work

Every calculator shows the tariff and usage assumptions behind its estimates, and lets you adjust them.

Calculations use current ARMS residential tariffs and local conditions, not generic international figures.

Estimates are a starting point for decisions — always confirm specifics with your bill or a professional.