Water calculators: fresh water, gray water, shower
How long will the fresh water tank last, when is the gray tank full, and how much water does an RV shower use? Here you can work out your water needs realistically.
Fresh water duration
Calculate water usage per person and day (drinking, dishes, showers, toilet) and how long your fresh water tank lasts – including gray tank and trip needs.
Open calculatorGray water tank
Calculate after how many days your RV's gray water tank is full – from water usage, gray water share and fill level – and whether the fresh or gray tank limits first.
Open calculatorShower water
Calculate the water usage per shower in an RV, how many showers a tank allows and how long the hot water from a 2.6 gal (10 L) water heater lasts.
Open calculatorWater tank fill time
Calculate how long filling your fresh water tank takes – with a hose (gal/min) or jugs – and how much weight comes on board.
Open calculator