Size the system
Consumption, production and physical fitSystem Size Calculator Guide
Why metered kWh beats an appliance list, how location drives the result, and the difference between peak load and total load.
Read the guide → ProductionSolar Yield Calculator Guide
P50 versus P90, the loss stack, temperature derating and what the weather model can and cannot see.
Read the guide → FeasibilityRoof Space Calculator Guide
Why 60 m² of roof is not 60 m² of panels, how layouts are packed, and how obstacles and parapets remove capacity.
Read the guide → OrientationSolar Panel Tilt Calculator Guide
The 0.87 × latitude rule, true south versus magnetic south, seasonal tilt and when adjustment is not worth it.
Read the guide → ElectricalString Sizing Calculator Guide
Cold-weather voltage, per-MPPT current, DC/AC ratio and how to read the layouts the calculator rejects.
Read the guide →Work out the money
Payback, loans and storage economicsSolar Payback Calculator Guide
What each input does, how to read every figure, and which numbers decide the answer versus which are forecasts.
Read the guide → FinancingSolar EMI Calculator Guide
Monthly payment, total interest, the real annual rate and the cash-flow gap while the loan is still running.
Read the guide → StorageGrid vs Battery Calculator Guide
Net metering as a virtual battery, the daily simulation, and when a physical battery actually beats the grid.
Read the guide → StorageBattery ROI Calculator Guide
Degradation, replacements, LCOS and why most batteries need a non-financial reason to buy.
Read the guide →Plan the next step
Backup, expansion and electric vehiclesBattery Backup Calculator Guide
How the bank, inverter and series-parallel layout are sized around the loads you need during an outage.
Read the guide → ExpansionSolar Expansion Calculator Guide
Adding an AC, EV charger or appliance to an existing system, and when the inverter must be replaced.
Read the guide → TransportEV vs Petrol Calculator Guide
Cost per kilometre, charging mix, payback, break-even distance and the solar array needed for daily driving.
Read the guide →Every calculator, one place
All twelve tools are free and run in your browser. Start with your bill, your roof or your load — the guides explain the rest.