Last updated October 10, 2026 · Report an error
Natural gas bills and appliance ratings mix energy units (BTU, therms) with volume-based billing units (CCF, MCF) somewhat interchangeably. This tool converts between them using a standard BTU-per-cubic-foot reference value.
How it works
Enter a value, choose the unit you're converting from, and the unit you want to convert to. A therm is defined as exactly 100,000 BTU; CCF and MCF use the commonly-cited EIA average of about 1,037 BTU per cubic foot of natural gas, which varies slightly by supplier and region.
- Enter value.
- Enter from.
- Enter to.
- Click Calculate to see your results.
Examples
A therm in CCF
1 therm (100,000 BTU) is approximately 0.96 CCF, using the standard ~1,037 BTU per cubic foot average heat content.
Who should use it
- Estimating a natural gas bill's energy content in BTU or therms.
- Comparing appliance BTU ratings against metered gas usage.
Industry applications
- Utilities and energy billing
- HVAC and appliance specifications
- Home energy audits
Advantages
- Covers both energy units (BTU, therm) and billing volume units (CCF, MCF).
- Uses a standard, commonly-cited EIA average heat content.
Limitations
- CCF/MCF conversions are approximate since actual gas heat content varies by supplier.
Common mistakes to avoid
- Treating CCF/MCF as exact energy units — they're volume units whose energy content varies slightly by gas supplier.
Best practices
- Check your actual utility bill for its specific BTU-per-CCF conversion factor if you need precise billing reconciliation rather than an estimate.
Tips
- For an exact bill reconciliation, use the specific BTU conversion factor printed on your gas bill rather than the general average used here.
Frequently asked questions
Unlike a therm (an exact energy unit), CCF and MCF measure a volume of gas — how much energy that volume contains depends on the gas's actual heat content, which varies slightly by utility and region.
100 cubic feet of natural gas (the "C" comes from the Roman numeral for 100) — a common billing unit on US gas bills.