Article — CCF to Gallons Converter
CCF to Gallons Conversion for Water and Gas Bills
CCF means centum cubic feet — 100 cubic feet of water or natural gas. One CCF equals exactly 748.052 US gallons, 622.883 UK imperial gallons, 2,831.685 liters, or 2.831685 cubic meters. American utilities use CCF (sometimes written HCF) as the standard unit on water and natural gas bills because 100 ft³ is a convenient size: residential customers consume in the single digits to low tens of CCF per month, keeping bill numbers readable.
Converting CCF to gallons matters when you want to estimate water-saving fixture payback, compare your usage to national averages, or check the bill math.
What is CCF?
CCF is a contraction of the Latin centum cubic feet, meaning 100 ft³. The Roman numeral C (for centum) gave the prefix CC, and the F stands for feet. Some utilities use the equivalent abbreviation HCF (hundred cubic feet) — the two are identical units with different names.
The cubic foot itself is defined precisely: 1 ft = 0.3048 m exactly (1959 international yard agreement), so 1 ft³ = 0.0283168 m³ exactly, and 1 CCF = 2.831685 m³ exactly. All other conversions derive from this and the gallon definition.
The US gallon was redefined in 1893 as exactly 231 cubic inches. This makes the gallon-to-cubic-foot ratio (1728 in³ / 231 in³) equal to 7.48051948... gallons per cubic foot — a non-terminating but rational decimal despite both definitions being exact. So 1 CCF works out to 748.051948... US gallons.
CCF to gallons math step by step
The conversion is one multiplication. Multiply CCF by 748.052 to get US gallons. For a typical 12 CCF monthly bill, that is 12 × 748.052 = 8,977 US gallons. Going the other direction, divide by 748.052: 10,000 gallons used ÷ 748.052 = 13.37 CCF.
For imperial gallons (UK), the factor is 622.883. For liters, 2,831.685. For cubic meters, 2.831685. All four are exact within the SI and the international yard-and-pound definitions.
1 CCF = 100 ft³ = 748.052 US gal1 CCF = 622.883 UK gal = 2831.685 L1 CCF = 2.831685 m³ ≈ 1.038 therms (gas, US avg)CCF vs MCF vs HCF
Three similar acronyms cause endless confusion. CCF and HCF both mean 100 ft³ — same unit, different abbreviation. MCF, however, means 1,000 ft³ (Roman M for mille = 1000). So 1 MCF equals 10 CCF or 7,480.52 US gallons.
Water utilities almost always use CCF or HCF. Natural gas utilities use either CCF or MCF depending on the customer size; small residential meters read in CCF, large commercial and industrial meters often read in MCF. Confusing CCF with MCF on a gas bill gives an answer that is off by 10×.
CCF on US water bills
The vast majority of US water utilities bill in CCF. The bill will show the previous and current meter reading (in cubic feet), the difference (in cubic feet), and then the converted volume in CCF. The CCF total is multiplied by the volumetric rate to get the consumption charge.
Typical US residential water rates run $3 to $15 per CCF for water alone. Sewer charges are usually added separately and often double the per-CCF cost. California cities like Santa Cruz and Santa Barbara have hit $20+ per CCF combined. Midwest and Southern cities with abundant water tend to stay under $5.
CCF on US natural gas bills
Residential gas bills usually quote consumption in CCF or therms (sometimes both). The conversion between CCF and therms depends on the heating value of the gas delivered: 1 therm = 100,000 BTU, and natural gas runs about 1,025-1,050 BTU per cubic foot in the US. The EIA national average is 1,038 BTU/ft³, giving 1.038 therms per CCF.
If your gas bill shows both CCF and therms, the ratio tells you your local heating value. Therms ÷ CCF = local BTU per cubic foot ÷ 1000. A bill showing 50 CCF = 51.9 therms means the gas is 1,038 BTU/ft³ — right at the US average.
CCF vs cubic meters internationally
Outside the US and Canada, water billing uses cubic meters almost universally. 1 m³ = 1,000 liters = 264.172 US gallons. Compared to CCF (= 2.831685 m³), the cubic meter is a smaller unit, so monthly readings in m³ are roughly 3× larger than in CCF.
European water rates per cubic meter run €1.50-€5.00 in most countries. Germany and the Netherlands sit at the upper end, southern European countries lower. To compare a US CCF rate to a European m³ rate, divide US dollars per CCF by 2.831685 to get dollars per m³.
Typical CCF usage at home
Per-person indoor water use in the US averages 60-100 gallons per day (220-380 L/day). For a family of four that is 240-400 gallons per day, or about 7,200-12,000 gallons per month, which converts to roughly 10-16 CCF/month. Outdoor irrigation in summer can double or triple this.
- Single-person household = 2-4 CCF water per month
- Couple, no yard = 4-8 CCF water per month
- Family of four = 8-15 CCF water per month
- With lawn irrigation = 20-50 CCF in summer months
- Residential gas, summer = 5-15 CCF (water heating only)
- Residential gas, winter = 60-200 CCF (heating + hot water)
Common CCF conversion mistakes
The first error is confusing CCF with MCF. A natural gas bill that quotes 50 MCF is ten times more gas than 50 CCF — and ten times the cost. Always double-check the unit symbol on the bill before doing math.
If you are comparing your usage to UK figures, remember that imperial gallons are about 20% larger than US gallons. 1 CCF = 748 US gal but only 623 imperial gal. Mistaking one for the other introduces a 20% error.
The second mistake is forgetting that water meters read in raw cubic feet, not CCF. The bill divides the meter reading by 100 to get CCF; if you check the meter directly, you need to do that division yourself.
A third gotcha is confusing the gallon variant when reading mixed-unit documents. UK government water reports use imperial gallons, US EPA reports use US gallons, and EU reports use liters or cubic meters. Always verify which gallon a source means before converting back to CCF — a 1,000-gallon figure could mean 1.34 CCF (US) or 1.61 CCF (UK), about a 20% spread. When in doubt, run the figure through liters first since 1 L is unambiguous globally.