Dripping Tap Calculator
How much water a dripping tap wastes in a day and a year, and what it costs at your water rate.
Count the drips in a minute.
How the dripping tap calculator works
Count the drips in a minute. A drip is about a quarter of a millilitre, so one drip a second is over 20 litres a day and nearly 8,000 litres a year — about 120 showers. Multiply by your water price per 1,000 litres for the annual cost. A washer usually fixes it in ten minutes.
Formula: litres per day = drips/min × ml per drip × 1,440 ÷ 1,000
Worked examples
| Inputs | Wasted per year | Note |
|---|---|---|
| One drip a second | 7,889 litres | 7,889 litres a year |
| A slow drip, 10 a minute | 1,315 litres | 1,315 litres |
| Two taps at 120 a minute | 15,779 litres | 15,777 litres |
FAQFrequently asked questions
How much water is a drip?
About a quarter of a millilitre, though drips range from 0.2 to 0.5 ml depending on the tap. Count the drips in a minute and adjust the volume if yours look large.
How much does a dripping tap cost?
One drip a second is close to 8,000 litres a year — at a typical price of a few dollars or pounds per 1,000 litres, that is a few dollars a year for the water alone, more if it is hot water.
Why fix it if it is that cheap?
The water is the equivalent of more than 100 showers a year, drips usually get worse, and a hot-water drip wastes energy too. A tap washer costs very little and takes ten minutes.
Is a running toilet worse?
Far worse — a leaking cistern can pass 200–400 litres a day, ten to twenty times a fast drip, and silently. If your water bill has jumped, check the toilet first.
Where these figures come from
- UK DESNZ / DEFRA — Greenhouse gas reporting: conversion factors — the flight, fuel and waste emission factors used here
- Scarborough et al. (2014), Climatic Change — Dietary greenhouse gas emissions — the per-diet daily emission figures
- US EPA — Technical Assistance Document for the Reporting of Daily Air Quality (AQI) — the PM2.5 breakpoints the air quality calculator uses
- UK Department for Energy Security and Net Zero — conversion factors — the official UK emission factors
Last checked: September 2026. Factors are taken from published government and peer-reviewed sources, each named on the page with its year.