RV camping tool · Off-grid duration
Boondocking Calculator
Find which resource is likely to end an off-grid stay first.
Updated 2026-08-12
Your shortest resource controls the stay
A large fresh tank does not help if the gray tank fills first or the battery reaches its reserve. This calculator compares independent planning limits and identifies the first one.
What is included
- Fresh water available after reserve
- Gray and black tank remaining capacity
- Usable battery energy after solar harvest
- Propane supply and daily use
Improve the estimate after one trip
Record starting and ending tank levels, battery energy and propane across a real trip. Replace generic estimates with your own gallons or watt-hours per person per day. Cold weather, furnace use and cloudy conditions can sharply change the result.
Frequently asked questions
How many days can I boondock?
The practical duration is the shortest result among fresh water, waste tanks, battery energy and propane.
Does solar make battery duration unlimited?
Only when average daily harvest equals or exceeds average daily consumption under real shade and weather conditions.
What usually runs out first?
It varies by rig and habits. Gray capacity, fresh water and battery energy are common limits, while cold-weather furnace use can make propane or battery the first constraint.
Related tools and guides
Official sources
Rules and penalties change. Confirm your situation with the issuing authority or a qualified professional before acting.