Everyday Money
Cost Per Bath Calculator
Enter bath volume, water price and optional heating cost to see cost per bath.
What does a bath cost?
A bath’s running cost is mostly water volume plus whatever you pay to heat that water. Enter litres used (a typical UK fill is roughly 80–150 L), your water tariff as money per cubic metre (1,000 L), and an optional heating/energy amount per fill if you know boiler or immersion cost. The tool adds water and heat for cost per bath, then scales by baths per week into weekly and yearly totals. Hot fills often dominate the bill compared with cold water alone. Compare habits with the cost per shower and cost per wash calculators using the same tariffs.
Worked example
100 L at £2.50 per m³ → water = (100/1000)×2.50 = £0.25. Add £0.40 heating → £0.65 per bath. Three baths a week ≈ £1.95 weekly and about £101 yearly.
Limits and assumptions
Tariffs, standing charges and heat losses vary by region and boiler. Partial fills and shared baths are not modelled unless you change the litre input.
Frequently asked questions
How do I find litres for my bath?
Many tubs list capacity; otherwise fill with a known bucket or use a flow meter. Depth of fill matters more than tub model name.
What belongs in the heating field?
Your best estimate of energy to raise that volume to bathing temperature — immersion kWh × rate, or a boiler-runtime guess.
Is water priced per litre or per m³?
Enter the m³ (1,000 L) price from your bill; the tool scales litres automatically.
Why compare with showers?
Showers often use less hot water per wash. Side-by-side costs show which habit is cheaper at your tariffs.