Water Usage Per Person Calculator

Work out water usage per person instantly with clear inputs, formula shown and shareable results.

About Water Usage Per Person Calculator

Personal water use is dominated by showering and flushing: an eight minute shower at 9 L/min is 72 litres, and five 6 litre flushes another 30. Typical UK use is around 140 litres per person per day, so a low-flow shower head is the single most effective reduction.

Formula

Water use

daily = shower minutes x flow + flushes x 6 L + other use

Worked example

With the default values below, Water Usage Per Person Calculator returns Daily water use of 157.00. Change any input above and every figure here is recalculated in your browser.

Inputs used

Shower time per day: 8 min
Shower flow rate: 9 L/min
Toilet flushes per day: 5 flushes
Other daily use: 55 L

Results

Daily water use: 157.00 L
Annual use: 57.31 m³
Shower use: 72.00 L
Annual cost at 2 per m³: $114.61

Step by step

1Values used
2Water use
3Daily water use= 157.00 L
4Annual use= 57.31 m³
5Shower use= 72.00 L
6Annual cost at 2 per m³= 114.61

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Frequently Asked Questions

What is a typical daily figure?

About 140 litres per person in the UK, 150-200 across much of Europe and over 300 in the United States, largely because of outdoor use.

What saves the most?

A 6-7 L/min aerating shower head and shorter showers. Together they can cut personal use by a third with no visible change in comfort.