Mobile setup tool
Water tank planner
Use your measured water consumption to compare tank capacity, refill needs, and the weight your vehicle would carry.
1. Water you actually use
US gallonsMeasure one job with a meter or a known container before you plan a tank. Add a reserve for hand washing, spills, or other uses outside the planned jobs.
2. The tank you are considering
US gallons and poundsUse the capacity and empty weight printed by the tank maker for the exact model, not a category average. Tank weight excludes the frame, mounts, pump, plumbing, and reel unless you add them to the next panel.
3. What the vehicle already carries
US pounds, optionalBoth fields are optional because only you can measure them. Leave either blank and the planner withholds the totals that depend on it. It never fills in a zero for a weight you did not enter.
Water tank plan
US gallons · US poundsNo plan is shown yet.
The planner shows numbers only when every required field holds a usable number. Nothing is estimated or filled in for you.
- Water used per job — Enter a value.
- Whole jobs between refills — Enter a value.
- Reserve you hold back — Enter a value.
- Tank capacity — Enter a value.
Summary to copy
Copy these results into your plan. This summary updates when you change an input.
Printing uses your browser, so the same dialog can save a PDF. The printed sheet keeps this plan and drops the form, the buttons and this box.
How much water should a detailing tank hold?
Multiply your measured water use per job by the number of jobs between refills. Add a reserve for other uses. Compare that amount with the capacity of the tank you are considering. A larger tank also means a larger possible load when full.
The calculation
- Water needed = gallons per job × jobs between refills + reserve.
- Planned fill = the smaller of water needed and tank capacity.
- Water weight = US gallons × approximately 8.34 pounds.
- Added load = water weight + empty tank weight + other load.
- Remaining payload = your entered payload capacity − added load.
The planner shows a shortage when the tank cannot hold the water needed. It compares the weight of a full tank and your planned fill separately. Missing weights stay unknown. Enter 0 only when you mean zero.
A worked example
These are example inputs, not measured operating results or an equipment recommendation. At 18.5 gallons per job, three jobs and a 10-gallon reserve need 65.5 gallons. A 75-gallon tank has 9.5 gallons of unused capacity.
The water weighs about 546.3 pounds at the planned fill, or 625.5 pounds when full. Add a 28-pound empty tank and 620 pounds of other load: the totals become 1,194.3 and 1,273.5 pounds. Against an entered 1,500-pound payload figure, that leaves 305.7 and 226.5 pounds respectively.
With a 60-gallon tank, the same plan is 5.5 gallons short. After the reserve, that tank holds enough water for two whole jobs at 18.5 gallons each. The planned fill is capped at 60 gallons.
Use the right vehicle figure
Payload is the combined weight of occupants and cargo. Gross vehicle weight rating (GVWR) includes the vehicle itself, so do not enter GVWR as payload. Check your exact vehicle's tire and loading label and owner manual. Include added equipment in other load. Count each item once.
A remaining allowance is only a comparison with the number you entered. Check total vehicle weight, axle and tire ratings, load distribution, tank mounting, and the equipment instructions separately. This tool does not approve an installation or model water movement.
Sources and limits
The U.S. Geological Survey gives 8.34 pounds per gallon. Its water density reference explains that temperature and dissolved substances change the weight. Treat the conversion as a planning approximation.
Ford's payload guidance explains the occupants-and-cargo label and how added equipment affects payload. It is a reference for the method; use the instructions for your own vehicle. Sources reviewed September 11, 2026.
Plan water supply and wash-water handling before you buy equipment. Continue with the mobile setup guide, build an equipment list, or price the service.