RV Cost Calculator RV Tank Duration Calculator
Plan your boondocking stays and manage your RV resources
Understanding RV Tank Capacity
Your fresh water, gray water, black water, and propane tanks determine how long you can boondock without hookups. This calculator helps you understand your limits and plan accordingly.
🚐 Quick Setup
Select your RV type to load typical tank sizes:
💧 Tank Capacities
Your clean water supply
Shower, sink, dishwater
Toilet waste only
Total for all tanks (80% capacity rule)
⚡ Usage Presets
Load common usage patterns:
👥 Occupancy
🚿 Water Usage
🔥 Propane Usage
📊 Tank Breakdown
💡 Tips to Extend Your Stay
Based on your limiting factor (Gray Water):
- Dump gray water more frequently (it fills fastest)
- Use biodegradable soap to dump in approved areas
- Reduce shower duration and frequency
- Scrape dishes well before washing
- Consider using disposable dishes for some meals
Important Notes
- • These are estimates based on typical usage patterns
- • Always dump tanks before they're completely full
- • Monitor tank levels with sensors when available
- • Plan for unexpected circumstances and weather changes
- • Fresh water usage can vary significantly by individual
Understanding RV Tank Systems
💧 Fresh Water System
Your fresh water tank stores clean water for drinking, cooking, showering, and washing. The size varies by RV type, from 20 gallons in small Class B vans to 100+ gallons in large Class A motorhomes.
Average daily usage per person: 10-20 gallons depending on conservation efforts. Showers are the biggest water consumer at 2-3 gallons per minute.
🚿 Gray Water System
Gray water is wastewater from sinks, showers, and washing. It typically fills faster than your black water tank. Many boondockers legally dispose of gray water in approved areas since it's relatively clean.
Pro tip: Gray water capacity often becomes your limiting factor. Use biodegradable soap so you can legally dump in more locations.
🚽 Black Water System
Black water is toilet waste only. This tank requires the most careful management and must be dumped at proper RV dump stations. Always keep the valve closed until the tank is 2/3 full.
Best practices: Use RV-specific toilet paper, add tank treatments, and never dump when below 2/3 full to maintain proper flow and avoid pyramid buildup.
🔥 Propane System
Propane powers your furnace, water heater, stove, oven, and possibly your refrigerator. Most RVs have two tanks with a total capacity of 14-40 gallons depending on RV size.
Usage note: Propane consumption varies dramatically by season. Winter heating can use 1-3 gallons per day, while summer might only use 0.5 gallons daily.
Boondocking Tips & Best Practices
🏕️ Extending Your Boondocking Stay
Water Conservation
- • Take "Navy showers" (wet, soap, rinse)
- • Use paper plates for some meals
- • Turn off water while brushing teeth
- • Collect shower warmup water for dishes
- • Use spray bottles for quick cleanups
Propane Conservation
- • Use electric when available at campgrounds
- • Cook outside with a camp stove
- • Add insulation to reduce heating needs
- • Use a catalytic heater for zone heating
- • Switch fridge to electric mode when possible
📍 Finding Dump Stations
Popular resources for locating dump stations include RV Parky, Allstays, and the Sanidumps app. Many rest stops, campgrounds, and even some gas stations offer dump services for a small fee ($5-15).
Free options: Some truck stops (Flying J, Pilot), Cabela's locations, and Camping World stores offer free dump stations for customers.
🔧 Tank Maintenance
- • Clean sensors regularly with tank wands or cleaning products
- • Use enzyme-based treatments for black tanks
- • Sanitize fresh water tank 2-3 times per year
- • Never leave black tank valve open at campgrounds
- • Always rinse black tank after dumping