Whole trip
0L
About 0 kg if you carry the whole trip’s fresh water (1 litre = 1 kg).
Each day
0L / day
Fresh water used
Grey water
0L trip
0 L / day
Breakdown by activity
Grey water is roughly the shower, washing up and laundry.
Start from a preset
Saved on this device
How to use
- Choose a preset if you want a head start, or keep the defaults.
- Set adults, optional children, and how many days you are away.
- Edit showers, washing up, and drinking. Tick laundry or cassette only if you use them.
- Totals update as you type. Refresh the page: your numbers stay on this device.
FAQ
How much fresh water do two people use per day in a motorhome?
There is no single number. A careful weekend for two is often 15–25 litres a day. A family week with daily showers can be 50–80 litres a day. Use the totals above for your own habits rather than a rule of thumb.
How much water does a motorhome shower use?
A short “navy” shower is often about 6 litres (roughly 1½ minutes). A normal wash is about 12 litres. A long shower can be 20 litres or more. Motorhome showers are usually around 4 litres a minute — much less than a house shower.
What is grey water, and how much should I plan for?
Grey water is what goes down the shower and sink. It is most of your fresh water minus drinking. Cassette flushes go in the toilet cassette (black waste), not the grey tank. Many vans fill the grey tank almost as fast as they empty the fresh one.
How long will my fresh tank last?
Type your tank size in litres. The note under the breakdown then says roughly how many days that tank lasts at your daily use. The Tanks page plans fresh, grey and cassette together.
How much does the water weigh?
One litre of water is about 1 kg. The trip total in litres is therefore about the same number in kilograms if you carry it all at once. A full 100 L tank is about 100 kg — that comes off your payload.
Do cassette toilet flushes use much water?
Usually not. A typical cassette flush is about 0.2–0.3 litres. Five flushes each for two people is around 2.5 litres a day. It still comes from the fresh tank, so it is in the total, but it does not fill the grey tank. The cassette empty planner turns those flushes into days between empties.
Should I include laundry?
Only if you will wash clothes on board. A basin or compact load is often about 15 litres. Many weekend trips skip it and use a campsite machine or wait until home.
Is this calculator accurate enough for trip planning?
It is a planning estimate, not a guarantee. Real use changes with leaky taps, longer showers, site showers, and how you wash up. Use it to compare habits and leave a margin, especially if you are wild camping.
Can I drink the water from the fresh tank?
Only if you treat the tank as drinking water: clean it, use a filter if you need one, and follow the tank and filler maker’s advice. Many people keep a separate bottle for drinking and use the tank for washing. This tool does not tell you the water is safe.
What is coming next?
Gas / LPG usage, the holding-tank planner, and the cassette empty planner are ready. Later tools include a gas bottle picker, hot water (gas vs electric), winterising volume, and an Aquaroll / top-up planner.