A simple household calculator

Water use calculator

Estimate your daily water use. Compare small changes and see what they could save.

Adjust the examples below. No account needed.

01 Your household

Start with the example, then make it yours. Durations and frequencies below are editable assumptions, not population averages.

02 Showers
Showers

Current

Planned

The current flow starts at EPA’s standard example, 2.5 US gal/min. Your actual flow may differ.

03 Bathroom faucets & toilets
Bathroom faucets & toilets

Current

Planned

Current examples: 2.2 US gal/min faucet; 1.6 US gal/flush toilet. WaterSense comparisons: 1.5 US gal/min and 1.28 US gal/flush. Faucet values apply to bathroom sinks, not kitchen taps.

04   Other use & water price Optional

Starts at zero. Add your own daily estimate for laundry, dishes, baths or outdoors if known. It stays the same in both scenarios. Do not add showers, bathroom taps or flushing again.

Use your own bill’s volumetric water price. No local tariff is assumed. Fixed fees, sewer, tiered pricing and water-heating energy are excluded.

Your result

Your water estimate

Calculating your example…

Email your results

Keep a copy of your estimate and plan. No newsletter signup.

A useful estimate starts with honest inputs.

This estimate covers showers, bathroom faucet running time, toilet flushing and any other daily volume you enter. It is not a full household water audit. Laundry, dishes, baths, irrigation and leaks are excluded unless you add your own estimate for them. A difference from your bill does not diagnose a fault.

What the examples mean

EPA WaterSense lists standard showerheads at 2.5 US gallons per minute and labeled showerheads at no more than 2.0. For bathroom faucets, the examples are 2.2 and 1.5 US gallons per minute. Toilets use an example of 1.6 US gallons per flush, compared with 1.28 for a WaterSense model. Actual fixture performance varies. The starting household size, durations and frequencies are illustrative assumptions, not EPA averages.

Read a fixture’s label or manufacturer information before using a flow or flush volume. If you measure flow, do so only with safe access and comfortable water temperature; do not climb, dismantle fixtures or work near electrical equipment. No changes to gas, electrical or water-heater settings are part of this tool.

Sources & calculation

Primary references: EPA WaterSense showerheads, bathroom faucets and residential toilets. Reviewed September 15, 2026. This independent tool is not an EPA certification or endorsement.

Use is calculated from frequency × duration × flow, or frequency × volume per flush, multiplied by the number of people where indicated. Annual estimates use 365 days; a month is one-twelfth of that year. Imperial values use US gallons only: 1 US gallon = 3.785411784 litres. Costs appear only when you enter your own volumetric price; fixed fees, sewer charges, tiered tariffs and energy costs are excluded.

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