Tools for the rig and the boat.
The calculators and checkers we reach for when we're sizing a house bank, a solar array, or the wire to carry it, whether that's in a van, an RV, or on a boat. Free, no sign-up, and built on the same research as our guides.
Off-grid by the numbers: 14 sourced facts from these calculators →
Why flat solar panels lose half their winter output, why your generator can't start the AC, why upload speed breaks video calls, and more, each computed and sourced.
ReferenceBoating by the numbers: a dozen things coastal cruisers get wrong →
Why an EPIRB beats a satellite communicator, why marine electronics cost more, and why 3M 5200 is the wrong sealant for almost every job, each sourced from our marine guides.
ReferenceThe real cost of owning a boat: what it actually costs in 2026 →
A 40-foot cruising sailboat costs $20,000 to $33,000 a year before you leave the dock, why the 10 percent maintenance rule is a myth, and why the average owner would be better off chartering, each sourced.
ReferencePower stations by the numbers: 43 portable units, analyzed →
Why a bigger watt-hour number does not mean it runs your gear, why the one non-LiFePO4 unit is the worst buy, and the real price-per-watt-hour sweet spot across eight brands.
ReferenceThe real cost of van life: what it actually costs in 2026 →
What van life really costs, sourced from real budgets: the van, the conversion, and the monthly total, plus the comparison everyone wants, van life versus the median US rent.
Sea
Boat Safety Gear Requirements Checker
Enter your boat's length and a few details, and see the gear the US Coast Guard generally requires you to carry, plus the gotchas owners trip on.
Open the checker → CalculatorSailboat Battery Bank & Solar Calculator
Turn your onboard loads into the house-bank size, solar array, and charge-controller numbers you actually need.
Open the calculator → CalculatorAnchor Size & Scope Calculator
Size the anchor for your boat, then get the scope and rode to deploy for the conditions you're anchoring in.
Open the calculator → CalculatorBoat Fender & Dock-Line Size Calculator
One boat length gives you the fender diameter and count, plus the dock-line diameter and the length to cut your bow, stern, and spring lines.
Open the calculator → CalculatorMarine DC Wire-Gauge Calculator
Enter your load, run length, and voltage for the AWG that satisfies both voltage drop and ampacity, the ABYC way, plus the fuse to match.
Open the calculator →Road
Solar Panel Angle Calculator
Enter your latitude and get the optimal year-round, summer, and winter tilt for your panels, which way to face, and how much energy you gain by tilting an RV, van, or boat array instead of leaving it flat.
Open the calculator → CalculatorGenerator Sizing Calculator
Tick the appliances you'd run at once and get the running watts, the starting (surge) watts, and the generator class to buy, sized on the single biggest startup surge that trips undersized units, with the carbon-monoxide rule front and center.
Open the calculator → CalculatorTrailer Tongue Weight & Towing Payload Calculator
Enter your loaded trailer weight and your truck's door-jamb payload for the target tongue-weight range and how much payload the load uses, plus GCWR and tow-rating margins. Numbers and ranges only, never a safe-to-tow verdict.
Open the calculator → CalculatorRV Solar & Battery Calculator
List your rig's 12V loads and this tool sizes the house battery bank, solar array, charge controller, and inverter an off-grid RV or van actually needs.
Open the calculator → CalculatorRV Battery Runtime Calculator
Enter your battery bank and the 12V loads you run, and see how long it lasts: days at your daily draw, the fridge-only figure, and hours at a heavy load (with the lead-acid Peukert penalty).
Open the calculator → CalculatorPropane Tank Runtime Calculator
Pick your tank size and the propane appliances you run, and see how long it lasts: days of runtime, the furnace-only figure, and your daily BTU burn, with the cold-weather and CO cautions.
Open the calculator → CalculatorRV & 12V DC Wire-Gauge Calculator
Enter your load, run length, and voltage for the AWG that satisfies both voltage drop and ampacity, the NEC way for RV, van, and off-grid 12V DC, plus the fuse to match.
Open the calculator →Setup
Power Bank & Watt-Hour Calculator
Convert mAh to watt-hours, check whether it flies in your carry-on (the 100 and 160 Wh airline rules), and estimate how many times it charges your laptop. Uses the 3.7V cell figure airlines use, not the 5V output.
Open the calculator → CalculatorMobile Data Usage Calculator
Add up your video calls, streaming, and work to estimate your GB per month, then see the hotspot allowance you actually need, the number that matters more than an 'unlimited' headline.
Open the calculator → CalculatorInternet Speed Calculator
Set how many calls, streams, and people are online at once and get a recommended download and upload speed in Mbps, with upload flagged as the number that decides whether a hotspot or Starlink can carry your video calls.
Open the calculator →