Do you know how much water does a running toilet waste? If you don’t know, don’t worry. Just let me explain in detail for you.

Let’s go to dive into the main article to know the detail.

A running toilet can consume up to 150 gallons of water a day, and even less in the winter. It’s always good to check how much water you are wasting.

What is A Flapper?

The flapper is the plastic part of your leaking toilet tank. It’s responsible for “flapping” or closing by yourself depending on whether you have to pee or poop. So it helps keep gallon of water inside the bowl. While flappers are made out of cheaper materials today. Because they’re not as important as timer valves.

How Many Gallons Does a Running Toilet Use Per Day?

Here’s the calculation you should use to find out your daily water use. Depending on how old our tank is. It may have older flappers which consume more water than the modern one.

Calculate How Much Water Your Toilet Consumes thru The Day You read above that a running toilet can take 150 gallons of water in 24 hours when it does not flush. It uses an average amount of around 25-30% of its total volume (about 30 gallons) per day while sitting there idle or turned off. I mean during the nighttime or days without any activity.

How Much Water Does A Running Toilet Use?

Toilet water loss is measured in half-gallons per flush (HGPF). The more you know about your toilet’s leaking flapper and seal, the better. But we’ll show you how to calculate it so that all of us would be able to determine if our toilets waste 50% more than necessary.

For a 784 gallon built unit leaky Toilet: This test will tell you what percentage of its total volume 30 gallons represent on an average day. With the tank valve closed and normal water usage. Measure this number within six months after buying your tankless toilet. Otherwise, it may vary. But we do not recommend you to use the formula only as a rough approximation and error is ok or even acceptable in some cases. So don’t over-analyze this calculation. For an American standard toilet. So 3 years after buying your unit – measure its total volume 700 + H gallons = 784 gallons US standard Toilet.

Divide it by 30 = 0.25 x 784 / 300 parts per million (ppm) 10 ppm means that every 11/16th of water or flush valve has been consumed by the flapper valve for 24 hours since the tank was installed.

How to Determine If You Have A Toilet Leak?

To figure out if there is any kind of water leaks in your toilet, all you need to do is routinely check the level every day. After defecating or urinating extensively regardless around six times maybe around 12-14 times. Let it enuresis for another 24 hours without flushing. And then available whether anything changed about that tank volume measurement you take at first place after this period has passed by itself.

How much does A Leaky Faucet Cost?

On average, installation is about $65 and the cost of replacement parts varies. The good old caulking we had used on drainpipes can be bought for as low as 10 cents per tube anywhere in the country by your local hardware store. But there might also be more expensive alternatives and some fixtures sold individually. So either way, you check prices first!


Running toilet leak waste is important in your bathroom. Because of the waste dissolving in the water tank. So you need to replace it regularly. But don’t forget our old theory. It is more expensive than popularly thought by most people!