Two quick calculators for real RV life: one to estimate when you’ll need to dump, and one to estimate how long your propane will last.
These are planning tools — close enough to be useful, and honest enough to keep you from guessing.
Friendly warning: tank math is never perfect. A “quick rinse” becomes a full shower, and suddenly grey is full.
Use this to plan your next dump stop — and if you smell something you shouldn’t, don’t ignore it.
Tank Preset + Units
Tip: if you don’t know your tank sizes, check the RV spec sheet or the tank labels.
Tank Sizes
Grey usually fills first. Black tends to surprise you later… usually when you least want to deal with it.
Daily Use Assumptions
Advanced (override the assumptions)
If you override values, use the same unit system you selected above.
Quick Links
Want to keep tanks from turning into a science experiment?
If you’re new to dumping: gloves, a clear elbow, and a dedicated “sewer bin” are not optional. Ask me how I know.
Serious part: propane is safe when it’s respected. If you ever smell propane, shut things down and sort it out properly.
This calculator is for planning — not for ignoring common sense.
Tank Setup + Units
Numbers assume typical usable fill and typical appliance draw. Furnace usage is the big swing factor.
