Overview
A natural gas bill typically shows usage in CCF (hundred cubic feet) or therms. Understanding the relationship between the two, and how to convert either into more familiar energy units, makes it easier to track usage, compare against past bills, or estimate costs. This article explains what these units mean and how to convert between them.
What You Need
- Your gas usage figure from a recent bill, in CCF or therms
- Optionally, your utility's specific conversion factor if listed on the bill (otherwise this guide uses the standard approximation)
Steps
Identify which unit your bill uses. Look for "CCF" (raw volume) or "therms" (billed energy) next to your usage figure. Many bills show both.
Understand what CCF measures. CCF is hundred cubic feet of raw gas volume, the physical quantity your meter actually measures before any conversion.
Understand what a therm measures. A therm is a fixed unit of heat energy, exactly 100,000 BTU. It's what your utility actually bills you for, since it reflects the energy content of the gas rather than just its volume.
Convert CCF to therms if needed. Multiply your CCF reading by approximately 1.037 to estimate the therm value your utility likely used for billing.
Use the Natural Gas Unit Converter for instant conversion. The Natural Gas Unit Converter converts between CCF, therms, BTU, cubic metres, and kWh without manual calculation.
Convert to kWh if comparing against electric usage. If you want to compare your gas costs or consumption against your electric bill, convert your therm value to kWh using the same tool, or the general Energy Converter for other energy unit conversions.
Common Mistakes to Avoid
- Assuming CCF and therms are the same number. They're close (roughly a 1.037 ratio) but not identical, and treating them as interchangeable can cause small discrepancies when double-checking a bill.
- Using a generic conversion factor for a precise billing dispute. Your utility's exact factor may differ slightly from the standard 1.037 approximation. Check your bill or utility website for your specific factor if precision matters.
- Forgetting that gas usage varies seasonally. Heating-driven gas usage runs much higher in winter, and that's normal, not a billing error.
Formula & Methodology
Therms = CCF x 1.037 (standard approximation)
1 therm = 100,000 BTU (exact, by definition)
Worked example: converting 50 CCF (a typical monthly residential bill) to therms.
Therms = 50 x 1.037 = 51.85 therms
Converting that to kWh: 51.85 therms x 100,000 BTU/therm / 3,412.14 BTU/kWh is about 1,519 kWh, handy for comparing against your electric bill's usage in the same unit.