The short answer
- The capacities overlap more than you would guessManufacturer figures put a standard bath at 170 to 250 litres and a walk-in bath at 150 to 240, so a compact walk-in model can use less than a large standard bath.
- What changes is how much of that gets usedAn everyday bath as most households run one uses about 80 litres. A walk-in bath needs enough water to reach a seated person, so it draws much closer to its full capacity every time.
- It only shows up on your bill if you are on a water meterUnmetered households pay a fixed charge regardless of how much water they use, so the extra litres cost nothing there.
- Safety is the reason to choose one, not the water billThe amount of water involved is not usually enough to change the decision either way.
Figures throughout are litres per bath and pounds per year for context, not a reason on their own to choose for or against a walk-in bath.
How much each one holds
How much water a standard bath and a walk-in bath hold
The comparison usually made is tub capacity against tub capacity, and on that measure the two are closer than most people expect.
- An everyday bath, as most households run one80L
- A standard bath, filled to the overflow170–250L
- A walk-in bath, filled to sit in150–240L
Standard and walk-in bath capacities: Premier Care in Bathing, a UK walk-in bath retailer. Everyday-bath figure: the Energy Saving Trust's 'At Home with Water' report and the Consumer Council for Water, both citing 80 litres as the national average.
A UK walk-in bath retailer's own figures put a standard bath, filled to the overflow, at around 170 litres, with a bigger bath holding up to 250. A walk-in bath holds 150 to 240 litres depending on the model, so the ranges overlap: a compact walk-in bath can hold less water than a large standard one. Nobody, in practice, fills an everyday bath to the overflow. Left to fill however deep feels right, a bath uses about 80 litres on average, which is the figure that matters for comparing what a household uses now against what a walk-in bath would use.
Why it still uses more
Why a walk-in bath still tends to use more, even though the tub is not always bigger
A walk-in bath is stepped into empty and filled with the door already sealed, so there is no equivalent of running a shallower bath for a quicker wash.
The point of a walk-in bath is to cover a seated person to a useful depth, around the hips and lower body at least, and that takes most of the tub's capacity every single time it is used. An ordinary bath does not work that way: someone can run two inches for a quick wash or fill it close to the top for a long soak, and most households, most of the time, land somewhere well short of the top. That difference in habit, not the size of the tub, is what usually makes a walk-in bath's day-to-day water use noticeably higher than the bath it replaces.
Topping the water up partway through a soak, which the old advice on this page used to warn against, adds to the total either way, in a walk-in bath or an ordinary one. It is worth avoiding for cost, not because a walk-in bath makes it uniquely wasteful.
What it means for your bill
Whether the extra water shows up on your bill depends on your water meter
Water and sewerage bills work in two different ways in England and Wales, and only one of them changes with how a bath is filled.
On a water meter
Pay for what you use
Not on a meter
A fixed charge either way
Does it matter?
Why the water bill should not be what decides this
A walk-in bath is bought for safety and independence, and the water it uses is a small part of the sum next to that.
If a walk-in bath will let your parent bathe without help, or without the fear of a fall getting in or out of an ordinary tub, that is worth far more than the difference in a water bill. If it is the building work or the cost that gives you pause rather than the water, a level-access shower or a wet room does the same safety job without a bath to fill and drain at all, and either can be funded through a Disabled Facilities Grant of up to £30,000 in England, means-tested by income and savings, starting with a free occupational therapist assessment arranged through the council. Local authority funding covers how to ask for one. The complete guide to walk-in baths covers choosing a model, and home adaptations for a private carer covers what else in the house is worth changing alongside the bathroom.
Sometimes what would help most is not a different bath but somebody there for the wash itself. Bathing and toileting an elderly parent covers the practical side of helping with a wash, and washing fits inside an ordinary morning visit rather than needing a call of its own. Every carer found through PrimeCarers has had an identity check, a right to work check, an enhanced DBS check on the Update Service and an online interview before their profile appears in search results, and hourly visits for personal care cost around £18 to £25 an hour on PrimeCarers, with our fee included.
Questions
Questions families ask about walk-in bath water use
Usually, yes, but not because the tub itself is always bigger. A UK retailer's figures put a standard bath at 170 to 250 litres and a walk-in bath at 150 to 240, so the ranges overlap. What raises the water use is that a walk-in bath has to be filled to a working depth every time it is used, while an everyday bath as most households run one uses about 80 litres.
Between about 150 and 240 litres, depending on the model. Compact models designed for smaller bathrooms or households with a smaller boiler sit at the lower end of that range.
Only if your home is on a water meter, where you pay for what goes through the pipes. If your home is unmetered, the bill is fixed by the property's rateable value and does not change however much water a bath uses. Any household can ask its water company to fit a meter free of charge.
Possibly, through the WaterSure scheme, which caps a metered bill at the local average for households on a qualifying benefit with high essential water use. A short list of conditions qualifies automatically, and others can be considered with evidence from a GP. Citizens Advice on WaterSure has the detail.
No more than it would in an ordinary bath. Adding hot water partway through adds to the total either way, so it is worth avoiding for the extra cost rather than because a walk-in bath is unusually wasteful.
For most households, no. The amount involved is a modest addition to a metered bill and nothing at all on an unmetered one, set against the safety of bathing without stepping over the side of an ordinary tub. If the wait while it fills and drains bothers you more than the water does, how long that wait takes and the alternatives to a walk-in bath are worth reading before deciding.