Personal Water Footprint Calculator: Tap and Virtual Water

Evaluate your true daily water footprint combining domestic tap usage and invisible virtual water from diet, meat, and consumer goods.

Personal water footprint: tap water plus virtual water

A water footprint adds the water you use at home to the "virtual" water needed to produce your food and the goods you buy. With the default settings (average diet, 8-minute shower, 2 coffees a day), the tool reaches about 4,030 litres a day, 92% of it from food and under 6% from the tap.

The three items calculated (litres per day)

  • Household water: shower 12 L/min (7 L/min with a low-flow head), bath 150 L, toilet flush 7 L, washing machine 50 L per cycle, garden watering 15 L/min, plus a fixed 20 L for cooking and hygiene.
  • Food: flat amount by diet (4,500 L meat-heavy, 3,400 L average, 2,500 L flexitarian, 1,800 L vegetarian, 1,400 L vegan), plus 140 L per coffee and 30 L per tea.
  • Goods: 8,000 L per pair of jeans, 2,500 L per T-shirt, 12,000 L per smartphone, spread over the year or over how long you keep the phone.

The total is compared with a Western average of 4,200 L a day.

Worked example (default values)

8-minute shower × 12 = 96 L, bath 21 L, 5 flushes 35 L, 3 washes 21 L, 15 minutes of watering a week 32 L and the fixed 20 L: 226 L of household water. Average diet 3,400 L + 2 coffees 280 L + 1 tea 30 L = 3,710 L. 2 pairs of jeans, 6 T-shirts and a phone kept 3 years: 96 L. Total: 4,032 L a day, or 1,471.6 m³ a year, 4% below the reference average.

Limits

Virtual water is mostly rainwater taken up by crops, so it cannot be compared litre for litre with your water bill. The diet is a flat amount, not broken down by food. The food waste calculator applies 1,800 L to each kilo thrown away; this one assesses your whole consumption.

Sources and dates: amounts per diet, per cup and per item, and the 4,200 L daily average, are indicative values of the tool, commonly attributed to Water Footprint Network research but not verified; household flow rates are indicative values (checked 14/10/2026).

Frequently Asked Questions

What is virtual water?

It is the water used to produce a food or an object, mostly rain and irrigation water taken up by crops. In the tool it makes up over 90% of the default footprint: 3,710 litres a day for food against 226 litres from the tap.

How many litres of water does a cup of coffee take?

The tool uses 140 litres of virtual water per cup of coffee and 30 litres per cup of tea, indicative values that are widely quoted. Two coffees a day therefore add 280 litres to your daily footprint.

Does a vegetarian diet cut the water footprint much?

In the tool, moving from an average diet (3,400 L a day) to a vegetarian one (1,800 L) removes 1,600 litres a day, about 584 m³ a year. That is far more than a low-flow shower head saves (40 litres a day for an 8-minute shower).

How much water does a shower use?

The tool counts 12 litres per minute with a standard shower head and 7 litres with a low-flow one: an 8-minute shower uses 96 or 56 litres. A bath counts as 150 litres.

Is this tool really free?

Yes, all tools on Kristools are 100% free and accessible without registration.

Is my data protected?

Yes. All processing is performed directly and securely inside your browser. No personal data is sent to our servers.