Which uses the most water?
Baths use less
An average bathtub will hold about 180 litres (60 gallons) of water, although when we take a bath, we only tend to fill it to the top if we’ve accidentally left the taps running! On average, we use about 80 litres (18 gallons) of water when we take a bath, according to Waterwise, an independent, not-for-profit organisation promoting water efficiency and conservation.
When taking a shower, the amount of water we consume depends on the shower type, but either way, an “average” 10-minute shower uses more than a bath. A traditional shower will uses 12 litres (21 pints) of water a minute, while a power shower uses 15 litres (26 pints) a minute.
Bath water usage
80 litres (18 gallons)
Standard mixer shower water usage
120 litres (26 gallons)
Power shower water usage
150 litres (33 gallons)
Shower figures based on a 10-minute shower. Figures taken from Waterwise
Top tip: turn off the water earlier
Whether we take a bath or a shower, there are simple ways to reduce water use. The Consumer Council for Water advises that reducing the height of a bath by 2.5cm (1 inch) of water will save, on average, five litres (nine pints). Cutting a 12-minute shower in half will save 60 litres (13 gallons) of water.
If you have a water meter, you pay based on the water you use.
Which costs more in water charges?
Showers cost more (usually)
The price you pay for your water will depend on your regional water supplier and whether you have a metered or unmetered supply. If you have a water meter, the more water you use, the more you’ll have to pay. And with personal bathing making up 33% of our overall water usage, the amount you use when taking baths and showers will have a big impact on your bill.
To calculate the costs, we took the amount of water used in litres, converted it to cubic metres (by dividing by 1000), and then multiplied by £1.94 – the amount Anglian Water charges standard metered customers for each cubic metre of water in 2023/2024.
The price you pay will depend on your water supplier and whether you have a water meter, but this gives a good indication of the difference in cost.
Bath water costs
80 litres (18 gallons) = £0.15
Mixer shower water costs
120 litres (26 gallons) = £0.23
Power showers use even more water – up to 150 litres (33 gallons) – which costs £0.29
Which costs more to heat?
With more water to heat, a shower costs more
In the case of most baths, the water is heated by a boiler. This is also true of standard mixer showers. In these cases, our calculations are based on heating the water from 10°C (50°F) to a comfortable 40°C(104°F)C, a few degrees above normal body temperature, using a gas boiler. This works out at 0.03kWh (kilowatt-hour) of energy per litre.
Heating an 80-litre bath would therefore use 2.4kWh of energy and running a standard shower for 10 minutes (using 120 litres of water) would use 3.6kWh of energy. A power shower (using 150 litres of water) would use 4.5kWh of energy.
Under the current Energy Price Guarantee, the current cost of gas iscapped at just over 10p per kWh (until April 2024, although prices may fall before then. Rates vary by region and are higher if you don’t pay by direct debit or have a prepayment meter.)
However, we also need to take into account electric showers. Rather than use a boiler to heat water, an electric shower has a built-in element that heats up cold water from the mains. They are one of the most expensive appliances to run in the home, using between 7kW and 10.5kW. We’ll take 8.5kW as an average.
The Energy Price Guarantee for electricity is currently around £0.34 per kWh (again, there are regional variations). So to work out the cost to run 8.5kW shower for ten minutes, we divide by 60 minutes and then multiply by 10 to get the energy used in kWh, then multiply by 0.34.
Bath heating costs
£0.24 (2.4kWh x £0.10)
Mixer shower heating costs
£0.36 (3.6kWh x £0.10)
Power shower heating costs
£0.45 (4.5kWh x £0.10)
Electric shower heating costs
£0.48 (1.42kWh x £0.34)