Convert CCF or HCF water use from your bill to US gallons, or convert US gallons to CCF and find daily use from service days.
This compares usage across billing periods with different numbers of service days.
HCF is another label for 100 cubic feet.
Table of contents
How to use our CCF to Gallons Conversion Calculator
- Choose the direction that matches the unit beside your number: CCF or HCF to US gallons, or US gallons to CCF.
- Enter the water-use amount from the usage section of your bill, a meter-reading difference, or a prior calculation. You can type a matching suffix such as CCF, HCF, gal, or gallons.
- When converting CCF or HCF, enter days of service only if you want an average gallons-per-day result. Copy the actual number of days from the bill.
- Click Calculate. The first result is the converted volume; in CCF or HCF mode, the HCF result should equal the amount you entered because the two labels describe the same volume.
- For two bills with different service periods, compare average gallons per day instead of comparing total gallons alone.
Definitions
CCF: A water-use unit equal to 100 cubic feet. The name comes from centum, meaning one hundred.
HCF: Hundred cubic feet. For water use, 1 HCF is the same volume as 1 CCF.
US gallon: The US liquid gallon used in this calculator. It is not an imperial gallon or a dry gallon.
Days of service: The number of days covered by a utility bill. This is used only for the optional daily average.
Average water use per day: Converted US gallons divided by days of service.
Utility-bill rounding: A utility may state that 1 CCF equals 748 gallons. The more precise unit conversion is about 748.051948 US gallons. [1]
Common mistakes and quick fixes
Mistake: Treating 1 CCF as 1 cubic foot.
Fix: A CCF is 100 cubic feet, or about 748.05 US gallons.
Mistake: Thinking HCF needs a different conversion.
Fix: Enter the HCF number in the CCF or HCF direction. Both labels mean 100 cubic feet of water.
Mistake: Entering the amount due on the bill instead of water use.
Fix: Copy the usage number marked CCF, HCF, or gallons. A dollar charge cannot be converted to gallons without that utility's rate rules.
Mistake: Assuming every bill covers 30 days.
Fix: Use the actual days of service shown on the bill when calculating gallons per day.
Mistake: Using a comma as a decimal mark, such as 1,5.
Fix: Use a decimal point for decimals, such as 1.5. Use commas only in thousands, such as 1,500.
Limitations & Key Assumptions / Boundary Conditions
- This calculator converts water volume only. It does not estimate water, sewer, tax, or fixed service charges.
- Results use US liquid gallons, not imperial gallons or dry gallons.
- CCF and HCF are treated as the same 100-cubic-foot unit. Convert cubic feet, MCF, or other units to CCF before using this calculator.
- Average gallons per day is the total volume divided evenly across the entered service days. It cannot show water use on a particular day.
- A utility may round gallons on a bill or apply billing rules that are separate from this exact volume conversion.
Methodology
Conversion method
One CCF, also called one HCF, is 100 cubic feet. Using the US liquid-gallon definition, 100 cubic feet equals 57,600/77 US gallons, or about 748.051948 US gallons.
US gallons = CCF or HCF x (57600/77)
CCF = US gallons / (57600/77)
Daily average
If days of service is entered while converting CCF or HCF, the calculator divides the converted gallon total by that positive day count.
Average gallons per day = converted US gallons / days of service
Worked example
For 2 CCF over 4 days, 2 x 748.051948 equals 1,496.103896 US gallons. Dividing by 4 gives about 374.025974 US gallons per day.
Calculation rules
Zero is a valid water-use amount. Negative water use is rejected. Days of service may be blank, but an entered value must be greater than zero because dividing by zero is undefined.