Everyone says the shower uses less. But how much less, exactly?
The phrase “a shower uses less water than a bath” is one of those facts everyone repeats but nobody quantifies. And when you do quantify it, the numbers are so striking that you wonder why you did not switch sooner.
At Bathscape we prefer data over assumptions. So let us put real figures on the table: measured litres, euros calculated with current Valencia tariffs and the energy required to heat that water. No generous rounding, no laboratory scenarios.
Methodology: how the measurement works
Before quoting figures, it is worth explaining how they are obtained — because “catalogue data” and “real-use data” are not the same thing.
For the bathtub: consumption is measured by filling the bathtub to the usual use level (not to the overflow — nobody fills it that high) and measuring the volume with a flow meter on the water intake. Standard 170×70 cm bathtubs have a total capacity of 180–220 litres, but the typical use level sits at 150–200 litres.
For the shower: consumption depends on two variables: the showerhead flow rate (litres per minute) and the duration of the shower. The flow rate is measured with a flow meter or, at home, by filling a container of known volume and timing it. The duration… well, everyone is different.
According to the INE (Water Supply and Sanitation Survey, 2023), average domestic water consumption in Spain is 133 litres per person per day, of which approximately 34% goes to personal hygiene (shower/bath). That is roughly 45 litres daily per person for showering or bathing.
The data: bathtub vs shower, litre by litre
Bathtub consumption
| Bathtub type | Total capacity | Typical use level |
|---|---|---|
| Standard 150×70 cm | 150–170 L | 120–150 L |
| Standard 170×70 cm | 180–220 L | 150–200 L |
| XL 180×80 cm | 250–300 L | 200–250 L |
| Freestanding (island type) | 200–350 L | 170–280 L |
The figure we need for the comparison: a standard flat bathtub in Valencia (170×70 cm, the most common) uses between 150 and 200 litres per bath. We will use 175 L as the average.
There is a detail that is often overlooked: the water that enters cold and is partially drained to add more hot water when the temperature drops. That can add 10–15%. Realistic total: around 195 L per bath.
Shower consumption
Here the calculation depends on the showerhead and the time:
| Showerhead type | Flow rate (L/min) | 5-min shower | 8-min shower | 10-min shower |
|---|---|---|---|---|
| Conventional without limiter | 12–15 L/min | 60–75 L | 96–120 L | 120–150 L |
| Standard with limiter | 8–10 L/min | 40–50 L | 64–80 L | 80–100 L |
| Eco / low-flow | 6–8 L/min | 30–40 L | 48–64 L | 60–80 L |
| Eco with aerator | 5–6 L/min | 25–30 L | 40–48 L | 50–60 L |
Key figure: the average shower duration in Spain is 7.5 minutes according to INE data (2023). With a standard showerhead with limiter at 9 L/min, that is 67.5 litres.
But here is a significant nuance: a 10-minute shower with a conventional showerhead at 15 L/min uses 150 litres. In other words, a long shower with an old showerhead uses the same as a bath. The shower only saves water if the showerhead is efficient and/or the duration is reasonable.
The final comparison table
| Scenario | Litres per use |
|---|---|
| Bath in a standard bathtub | 175–200 L |
| 5-min shower with eco showerhead | 30–40 L |
| 7.5-min shower with standard showerhead | 60–75 L |
| 10-min shower with conventional showerhead | 120–150 L |
An efficient shower (eco showerhead, 5–7 minutes) uses 65–80% less than a bath. An inefficient shower (old showerhead, over 10 minutes) can use virtually the same amount.
Savings calculator: euros and cents
Let us translate litres into euros. For that we need two prices: the cost of water and the cost of the energy to heat it.
Water price in Valencia
According to the current tariffs from EMIVASA (Empresa Mixta Valenciana de Aguas) for 2026, the average domestic water price in Valencia, including supply, sewerage and levies, is approximately 2.80 €/m³ for average consumption (tier 2 of the progressive tariff).
In other words: every 1,000 litres cost 2.80 €. Or put differently: each litre costs 0.0028 €.
Cost of heating the water
To heat 1 litre of water from mains temperature (around 15 °C in Valencia, annual average) to 38 °C (shower temperature), you need to raise it by 23 °C.
Energy required: 1 litre × 23 °C × 1 kcal/(L·°C) = 23 kcal = 0.0267 kWh.
| Energy source | Price per kWh (2026) | Cost per heated litre |
|---|---|---|
| Natural gas | 0.065 €/kWh | 0.0017 €/L |
| Electricity (regulated tariff) | 0.15 €/kWh | 0.0040 €/L |
| Aerothermal (COP 3.5) | 0.043 €/kWh effective | 0.0011 €/L |
With natural gas (the most common installation in Valencia flats), heating the water for a bathtub (175 L) costs approximately 0.30 €. Heating the water for a 5-minute eco shower (35 L) costs 0.06 €.
Annual savings scenarios
Family of 4, daily use:
| Scenario | Litres/year | Water cost | Energy cost (gas) | Annual total |
|---|---|---|---|---|
| Everyone baths (1 bath/day each) | 255,500 L | 715 € | 434 € | 1,149 € |
| Everyone showers 8 min, standard head | 102,200 L | 286 € | 174 € | 460 € |
| Everyone showers 5 min, eco head | 51,100 L | 143 € | 87 € | 230 € |
Savings from switching bathtub to eco shower (5 min): 919 € per year. Nearly one thousand euros.
Savings from switching bathtub to standard shower (8 min): 689 € per year.
These numbers are not theoretical. They are basic arithmetic with real Valencia prices. If your family baths daily and you switch to efficient showers, the bathtub-to-shower conversion (which runs at around 3,500–5,000 € at Bathscape) pays for itself in water and energy savings within 4–6 years. From that point on, it is pure net savings.
The environmental impact: data worth noting
Beyond the wallet, there is an environmental dimension that deserves attention.
Water footprint
Spain is the third EU country with the highest water stress, according to data from the European Environment Agency. Valencia in particular depends on limited water resources (Turia, Júcar, Tajo-Segura transfer). Every litre saved in the shower is a litre available for other uses.
The annual difference for a family of 4 that switches from bathtub to eco shower is 204,400 litres. That is 204 cubic metres. For context: it is the equivalent of filling an 8×4-metre swimming pool 6 times.
Carbon footprint
Heating water with natural gas emits approximately 0.2 kg of CO₂ per kWh. The difference between bathtub and eco shower for a family of 4 represents savings of around 1,300 kWh annually, equivalent to 260 kg of CO₂ per year.
For those who think that is negligible: 260 kg of CO₂ is the same as the emissions from 1,600 km in an average petrol car. That is like driving from Valencia to Bilbao and back. Every year.
How to maximise savings: three specific measures
1. Showerhead with aerator and flow limiter
An eco showerhead mixes air with water, maintaining the sensation of pressure while using less flow. Going from 12 L/min to 7 L/min reduces consumption by 42% without a noticeable difference in the experience.
Price: 20–60 €. Installation: unscrew the old one, screw in the new one. One minute.
This is what we call at Bathscape “the highest-impact improvement with the lowest investment.” It is not glamorous, but the numbers do not lie.
2. Thermostatic mixer
We have already explained this in detail in our thermostatic vs single-lever comparison, but the summary is: the thermostatic mixer eliminates the 8–12 litres wasted adjusting the temperature manually with each shower. For a family of 4, that is 11,000–17,000 litres per year.
3. Timer or consumption display
It sounds like a psychological trick, and it is — but it works. A display showing litres consumed in real time during the shower reduces average duration by 20–25%, according to studies from Imperial College London published in 2023. Some systems like Amphiro install between the mixer and the showerhead and display consumption without needing mains power.
If you are going to convert your bathtub to a smart shower, level 2 and 3 systems already include integrated consumption monitoring.
The endless-shower trap
We need to be honest about a data point that many guides omit: the shower only saves water if it is reasonably short. A 15-minute shower with a conventional showerhead at 12 L/min uses 180 litres. More than a bath.
This is not an argument in favour of the bathtub. It is an argument in favour of showering with an efficient showerhead and some awareness of time. Technology helps (thermostatic mixer, consumption display, timer), but ultimately the most determinant variable is user behaviour.
In our data from installations with consumption monitoring, we have observed that simply having a visible display reduces average shower time from 8.5 to 6 minutes. No restrictions, no lectures. Just visible data.
Frequently asked questions
How much does a litre of hot water actually cost in Valencia?
Adding water (EMIVASA) and energy (natural gas), each litre of hot water at 38 °C costs approximately 0.0045 €. It seems trivial, but multiplied by the 100–200 litres of a bath and by 365 days a year, it accumulates quickly.
Do eco showerheads really not reduce perceived pressure?
The good ones do not. Showerheads with aeration technology (Grohe EcoJoy, Hansgrohe EcoSmart, Roca Cold Start) mix air with water and create a jet that feels voluminous despite carrying less water. The difference from a conventional showerhead is practically imperceptible in the shower experience.
How much does a real family save by switching from bathtub to shower?
With real Valencia data: between 460 € and 920 € per year in water and energy, depending on shower duration and showerhead type. The average for a family of 4 is around 600 € annually.
If I have solar panels for DHW, are the savings still significant?
The energy savings are reduced (the sun heats the water “for free”), but the water savings remain identical. And in Valencia, with an average of 300 sunny days a year, solar panels will cover a large part of DHW demand, but you still pay EMIVASA for the water. Total savings with solar panels are around 350–500 € annually (water only + energy not covered by solar).
Conclusion: the litres do not lie
The comparison is objective: an efficient shower uses between 65% and 80% less water than a bath. The financial saving for an average Valencia family is between 460 € and 920 € per year. And the environmental impact — more than 200,000 litres and 260 kg of CO₂ saved annually — is significant.
But the savings do not come from switching bathtub to shower alone. They come from combining the conversion with an efficient showerhead, thermostatic mixer and, budget permitting, consumption monitoring. Without those three pillars, the shower can use almost as much as the bathtub.
Want to calculate the exact savings for your case? Use our configurator to design your shower and we will show you a personalised consumption estimate. If you are considering the switch, you may also find it useful to know how much an efficient bathroom really saves with local data from Valencia and our smart-tech designs that integrate monitoring technology as standard.
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