The cost of a bath or shower - update

I last looked at the cost of a bath versus a shower back in 2015 [1]. Given the general increase in prices since then I was not too surprised at the increase in cost.

The total cost includes the cost of the water and the energy to heat it. It is still the case that the water cost is a bit more than the energy cost, despite the increase in the cost of energy, as long as the heat source is gas rather than electricity. Previously I had described two showers - a typical shower (7 minutes at 8l/min) and a shorter low-flow shower (4 minutes at 6 l/min). For both of these the water was heated with gas. This time I have compared the cost of a short low-flow electric shower with a typical shower heated by gas. Electric showers usually do have a lower flow rate, simply because you would need too much power to heat the water at the flow rate you get from a hot water cylinder (which is pre-heated).

Summary of assumptions.

• 88 litres for a bath vs. 24 litres for a short, low-flow shower (4 minutes at 6 l/min) or 56 litres for a typical shower (7 minutes at 8 l/min).
• bath water at 41°C and shower water at 39°C coming in from the mains at 14°C.
• Gas for heating at 85% efficiency.
• Electricity at 100% efficiency.
• Water price: 
• 0.139p/litre for clean water [2a].
• 0.256 p/litre for sewerage (from Anglian Water) [2b] charged for 90% of the clean water supplied.
• Energy prices based on the current price caps: 26.1p/kWh for electricity and 7.33p/kWh for gas [3].

Overall findings: 

• Costs (using gas for heating) are up nearly 60% from 2015. The increase for the water and for the energy are surprisingly similar.
• This increase is slightly more than general inflation which was 43% over the same period [4].
• The cost of a bath is now about 56p (depending on the size and depth of your bath), a typical shower 35p
• In 2015 this was 36p for the bath and 22p for the shower.
• When heating by gas the cost of the water is nearly 60% of the total cost.
• When heating the water by electricity, the cost of the water is only 33% of the total.

[1] How much does your bath or shower cost? (Energy thoughts and surprises)

[2a] Metered Charges (Cambridge Water)

[2b] Our standard charges (Anglian Water)

[3] What is the energy price cap? (Energy price cap unit rates and standing charges, (OFGEM)(cap as of August 2026)

[4] Inflation calculator (Bank of England)