Sizing a solar + battery system for full-time off-grid

Question I get constantly: "how much solar/battery do I actually need?" Rough rule of thumb before you buy anything:

- Add up your daily DC loads (fridge, fans, lights, water pump, phone/laptop charging) in amp-hours
- Add your inverter loads (anything AC — coffee maker, microwave, CPAP) converted to DC amp-hours at your battery voltage
- That total is your daily consumption — multiply by 1.5-2x for a buffer on cloudy days
- Battery bank should cover 2-3 days of that consumption without any solar input
- Solar array should be able to replace a full day's usage in about 5-6 hours of decent sun

Victron's MPPT calculator and a clamp meter for a few days of real usage will get you a much better number than any generic chart. What are you running — and is this a build from scratch or an upgrade to something already installed?