Off-Grid Organic combines calculators, formulas and worked examples so you can size an off-grid system from your own numbers instead of generic rules of thumb. Pick the tool that matches the question you are trying to answer.
Solar and power system sizing
- Off-Grid Solar System Sizing Calculator – estimate solar panel watts, battery bank size, inverter capacity and backup days.
- MPPT Charge Controller Sizing Calculator – size controller current, PV voltage and battery charging for 12V, 24V and 48V systems.
- Battery Cable Size Calculator – calculate cable thickness, current load and voltage drop.
- 12V vs 24V vs 48V Solar System Guide – compare current, cable size, inverter limits and efficiency before choosing a system voltage.
Battery sizing and upgrades
- Off-Grid Battery Bank Sizing – calculate amp-hour and kilowatt-hour needs from depth of discharge, autonomy days and inverter efficiency.
- How Many Batteries for a 3000W Inverter? – battery sizing for 12V, 24V and 48V systems with runtime examples.
- Upgrade Lead Acid to LiFePO4 Calculator – convert Ah, Wh and depth of discharge when replacing lead-acid batteries.
- LiFePO4 vs Gel Battery – compare lifespan, charging speed, depth of discharge and lifetime cost.
Camper vans and mobile systems
- Camper Van Electrical System Calculator – size battery bank, solar panels, inverter, MPPT, DC-DC and shore charger together.
- Camper Battery Size Calculator – calculate Ah, kWh, runtime and the number of LiFePO4, AGM or gel batteries.
Greenhouse, garden and land
- Solar Greenhouse Ventilation Fan Sizing – calculate exhaust fan CFM, daily energy use and solar panel size.
- How Much Land Do You Need to Be Self-Sufficient? – compare garden sizes and estimate your household land needs.
Water
- Rainwater Harvesting System Size Calculator – estimate annual water collection, tank size and roof runoff.
Inverters, batteries and panels
- Inverter Size Calculator – continuous watts, start-up surge, DC current and fuse size.
- Battery Runtime Calculator – how long a LiFePO4 or lead-acid bank runs a given load.
- Off-Grid Fridge Power Calculator – real daily fridge use by room temperature, plus battery and solar size.
- Solar Panel Tilt Angle Calculator – winter, summer and year-round tilt for your latitude.
- Series vs Parallel Panel Calculator – check every string layout against your MPPT voltage and current limits.
Garden, livestock and kitchen
- Chicken Coop Size Calculator – coop floor, run, perches, nest boxes and vents for your flock.
- Compost C:N Ratio Calculator – mix greens and browns to a hot-composting 30:1.
- Fermentation Salt Calculator – exact salt for sauerkraut or brine.
- Seed Starting Date Calculator – indoor sowing and planting-out dates from your last frost date.
How to use these tools
Calculator results are planning estimates based on the values you enter and the assumptions stated on each page. Always verify critical values against the manufacturer documentation for your equipment and follow local electrical and building requirements. You can read more about how we build and check our tools on the About page.