Is your water use normal for your household?

What CCF, HCF, kgal and m³ mean on a water bill

Water meters count volume, and utilities pick the unit. The most common in the US is the CCF, short for centum (hundred) cubic feet: one hundred cubic feet of water, which EPA puts at 748 gallons (EPA (accessed October 4, 2026)). HCF (hundred cubic feet) is the same unit under a different name, so 1 HCF is also 748 gallons. Pictured, a CCF is a cube of water about 4.6 feet on each side (the cube root of 100 cubic feet). At EPA's 82-gallon average, a two-person home uses about 6.6 of those cubes a month: 82 × 2 × 30 ÷ 748.

Utilities that bill in gallons often print usage in kgal (thousands of gallons), so 7 kgal means 7,000 gallons. Some bill in cubic meters (m³); one cubic meter is about 264 gallons, a bit more than a third of a CCF. Some meters read in plain cubic feet, where 1 ft³ is about 7.5 gallons. The exact factors this tool uses come from NIST's conversion tables (NIST (accessed October 4, 2026)).

Why it matters: a bill that says “9” means very different things in each unit. Nine CCF is about 6,700 gallons, nine kgal is 9,000, and nine cubic meters is about 2,400. Before you compare your bill with a neighbor's, an online average or last year's statement, convert both to gallons and divide by the number of days in each billing period. That one step removes most of the false alarms people bring to their utility.

Where the two benchmarks come from

82 gallons per person per day is EPA WaterSense's figure for water used at home, citing the US Geological Survey's 2015 estimate (EPA (accessed October 4, 2026)). EPA's bill guide turns it into a household check: a family of four uses around 10,000 gallons in a 30-day period (EPA (accessed October 4, 2026)). The arithmetic is 82 × 4 × 30 = 9,840 gallons, which is why the top of this tool's range for four people is 328 gallons a day.

58.6 gallons per person per day is average indoor use in single-family homes in the Water Research Foundation's Residential End Uses of Water study, Version 2 (REU2016), which logged 23,749 homes across 23 utilities in North America. The same report puts indoor use at 138 gallons per household per day, with an average of 2.65 people per home (WRF REU2016 executive report (accessed October 4, 2026); project page: WRF (accessed October 4, 2026)). WRF published a Version 3 study in 2026; its full results are for subscribers, so this page uses the published 2016 figure.

Indoor use is the steadier number: toilets, showers, faucets, clothes washers and leaks. Total use adds whatever happens outside, which swings with climate. The gap between 58.6 and 82 is roughly in line with EPA's average outdoor share, which is why the tool shows a range rather than a single “normal.” A home under 58.6 per person is using less than the average home uses indoors; a home at 82 is average once you count the yard.

Why summer bills look different

Outdoor watering is the biggest seasonal swing. EPA says outdoor use is more than 30% of total household use on average and can reach 60% in arid regions (EPA (accessed October 4, 2026)). REU2016 found outdoor use far more variable than indoor use, with homes in warmer climates continuing to irrigate in winter (WRF (accessed October 4, 2026)). So a summer bill that is 50% higher than a winter bill can be completely normal for a house with a lawn, while the same jump in January points somewhere else.

That is why the tool asks about watering. With “some” watering, the top of the range moves to about 84 gallons per person a day; with “heavy” watering it moves to about 147. Those are estimates built on EPA's outdoor shares, not your utility's data, and they are deliberately generous so the tool flags real outliers rather than every July bill. If your summer use is above even the heavy band, look for a stuck irrigation valve or a timer running more often than you think.

The fair comparison for a summer bill is last summer's bill in gallons per day. If your statement has a usage-history graph, use the same month last year.

Why sewer charges follow your water use

Most homes have one meter, on the water coming in. Nobody meters what goes down the drain, so utilities bill sewer from the water meter as well; EPA notes that many utilities have only one meter and charge both water and sewer on the water entering the house (EPA (accessed October 4, 2026)). That means every extra gallon usually costs you twice: once as water, once as sewer.

Some utilities soften this for outdoor use. Seattle Public Utilities, for example, bases single-family sewer bills on actual winter water use (November through April); if you use more in summer, your summer sewer bill is based on your winter average, so you are not charged sewer for lawn watering and car washing (SPU (accessed October 4, 2026)). Check your own bill for the words “winter average” or “sewer cap.” If they are not there, high summer use raises sewer too.

What “above the range” usually means

Being above the range is not proof of a leak. More people at home, guests, a new appliance, a pool fill or heavy watering all show up the same way on the meter. But leaks are common enough to rule out first. REU2016 measured average leakage of 7.9 gallons per person per day, with some homes leaking as much as 600 gallons a day (WRF (accessed October 4, 2026)), and EPA estimates the average family can waste 180 gallons a week from household leaks (EPA (accessed October 4, 2026)).

The two-hour meter test settles it: turn everything off, read the meter, wait two hours, read it again. EPA says that if it changes at all, you probably have a leak, and a few drops of food coloring in the toilet tank will show a flapper leak within 10 minutes (EPA (accessed October 4, 2026)). A single faucet dripping once a second wastes more than 3,000 gallons a year by EPA's count, which is about 8 gallons a day, small on its own but easy to fix.

Recap

• Convert to gallons (1 CCF = 748), then divide by days and by people.
• Typical is between 58.6 (indoor) and 82 (total at home) gallons per person a day, more with a lawn in summer.
• Above the range: do the two-hour meter test before anything else, then look outside.

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