The Calculators
Pick a tool. Each one runs locally in your browser — nothing leaves your device, and they all work offline once loaded.
Solar Panel Sizer
How many watts of solar do you need to keep your batteries topped off?
Open calculator →Battery Bank Sizer
Right-size your house batteries for how long you actually camp off-grid.
Open calculator →Generator Sizer
Find the right wattage generator for your RV's appliances and AC unit.
Open calculator →Fresh Water Calculator
How many gallons of fresh water you need for your trip and crew.
Open calculator →Propane Usage Estimator
Estimate propane consumption for furnace, fridge, water heater and stove.
Open calculator →Holding Tank Duration
How many days until your gray and black tanks fill up at your usage rate.
Open calculator →RV Trip Cost Calculator
Total trip estimate: fuel, campgrounds, propane, food and incidentals.
Open calculator →Towing & Payload Check
Verify your tow vehicle can safely handle your trailer's weight.
Open calculator →Field Guides
Plain-English explainers for the concepts behind the calculators. No fluff.
Boondocking Power Basics: Understanding Watts, Amps and Amp-Hours
The plain-English guide to RV electrical units. Master watts, amps, and amp-hours so you can size your system right.
Read guide →RV Water Conservation: Stretch Your Fresh Tank Twice as Far
Real techniques full-timers use to cut water use by 50%+ without feeling deprived.
Read guide →Solar vs. Generator for RV Boondocking: An Honest Comparison
Each one has clear strengths. Here's how to decide which (or both) belongs on your rig.
Read guide →Why we built these
Most "RV calculators" out there are either bloated lead-gen funnels for solar dealers, or ancient spreadsheets nobody updates. We needed quick, accurate tools for our own builds — battery banks, water budgets, propane runs — so we built them clean and put them on the open web.
Every calculator here uses the same physics and industry standards a real installer would use. The numbers come from manufacturer spec sheets, the NEC, and decades of forum lore distilled into formulas you can actually trust.
Bookmark this page or add it to your phone's home screen. Many of our calculators work without an internet connection once they've loaded the first time.