Natural Gas Bills Explained: How Commercial Gas Is Billed

Natural gas is often the largest single line on a commercial building's utility budget in heating climates, yet the bill that explains it is written in a language most facilities teams never fully learn. One meter reports cubic metres, another reports hundreds of cubic feet, the supplier quotes dekatherms, and the accounting export lists gigajoules. Before you can compare a rate, catch an overcharge, or roll gas into an emissions inventory, you have to reconcile all of that into one consistent number.

This guide breaks a commercial gas bill into the parts that actually drive cost: the volume and energy units and how to convert between them, the split between the commodity you buy and the delivery you pay to move it, the difference between fixed and variable charges, the current state of the Canadian federal carbon charge on gas, and how a US gas bill is structured differently. The goal is a bill you can read line by line and defend.

The units problem: m3, GJ, therms, Mcf, and Dth

Gas is metered by volume but sold by energy content, and different markets pick different units for each. Canadian utilities meter in cubic metres (m3) and often present a billing quantity in gigajoules (GJ). US utilities meter in cubic feet, then bill in hundreds of cubic feet (Ccf) or thousands of cubic feet (Mcf), or convert to therms. Wholesale suppliers and interstate pipelines usually quote dekatherms (Dth).

The conversions are fixed once you know the heat content of the gas. The US Energy Information Administration uses an average heat content of about 1,037 Btu per cubic foot, which makes one thousand cubic feet (Mcf) equal to roughly 1.037 MMBtu, or 10.37 therms (EIA). A therm is 100,000 Btu by definition, and a dekatherm is exactly one MMBtu, so one Dth equals ten therms. Working from the same EIA heat content, a cubic metre of gas (about 35.3 cubic feet) carries roughly 0.0386 GJ, though the exact figure varies with the local heating value your utility publishes.

The practical trap is mixing a volume unit with an energy unit and never noticing. A rate expressed in dollars per GJ and a meter reading in cubic metres cannot be compared until both sit on the same basis. Every conversion above depends on heat content, so when you need audit-grade numbers, use the heating value your utility actually printed on the bill rather than a generic average.

The two halves of a gas bill: commodity versus delivery

Almost every regulated gas bill splits into two economic halves. The first is the commodity, also called the gas supply charge: the cost of the molecules themselves, priced close to a market index and typically passed through with no utility markup. The second is delivery, also called distribution or transportation: the cost of the pipes, compressors, meters, and service that move the gas to your building. Delivery is where the utility earns its regulated return, and it is the half that a rate class or tariff choice actually changes.

Enbridge Gas in Ontario shows this split clearly. For its commercial Rate 6 class, the gas supply commodity charge decreased to 10.2004 cents per cubic metre effective April 1, 2026, down from 13.7858 cents (Enbridge Gas). Separately, the charge to transport gas into the Ontario system moved to 6.251 cents per cubic metre on the same date (Enbridge Gas). Delivery charges are billed on top of both. On a US bill the same structure appears, though the labels differ: a supply or gas cost line, then a distribution or delivery line, each with its own per-unit rate.

• Gas supply / commodity charge: the priced cost of gas, usually a pass-through pegged to a market index.
• Transportation charge: moving gas from the supply basin into the local distribution system.
• Delivery / distribution charge: the local utility's pipes, meters, and service, where the regulated margin sits.
• Fixed customer / service charge: a flat monthly amount that does not change with volume.
• Rider and adjustment lines: conservation program charges, cost true-ups, and taxes.

Fixed versus variable charges

Within those halves, each line is either fixed or variable. Fixed charges (the monthly customer or facility charge) are the same whether you burn zero gas or your annual peak. Variable charges scale with consumption. This matters for two reasons. First, a building with low but steady gas use can see fixed charges dominate its effective rate per unit, so cutting volume alone barely moves the bill. Second, when you normalize cost per GJ or per therm for benchmarking, the fixed component distorts the comparison unless you separate it out. Reading the ratio of fixed to variable is the fastest way to understand whether efficiency projects or rate changes will pay back.

The federal carbon charge on natural gas in Canada

For several years the single most confusing line on a Canadian gas bill was the federal carbon charge, a per-unit fuel charge that climbed every April. That line no longer applies to consumers. On March 14, 2025, the Government of Canada announced it would remove the fuel charge effective April 1, 2025, by setting all fuel charge rates to zero (Canada Revenue Agency). Immediately before removal, the marketable natural gas rate had reached 15.25 cents per cubic metre following its April 1, 2024 increase (Enbridge Gas). Since April 1, 2025, the consumer-facing carbon charge line on a gas bill is zero.

How US gas bills differ

A US commercial gas bill covers the same commodity-plus-delivery structure, but the presentation and the market around it differ in ways that matter when you consolidate a cross-border portfolio.

• Units: US utilities bill in therms or in Ccf and Mcf rather than cubic metres and gigajoules, so a portfolio spanning both countries needs a conversion layer before any comparison.
• Retail choice: in many US states, commercial customers can buy the gas commodity from a competitive marketer while the utility still handles delivery, which splits the bill across two vendors and two documents.
• Wholesale quoting: marketers and pipelines quote dekatherms, so a supplier contract in Dth has to be reconciled against a utility meter in Ccf.
• Price level: the US average price of gas sold to commercial consumers was about $10.97 per Mcf in 2025 (EIA), and per-unit prices vary widely by state and season.
• No federal consumer carbon charge: US bills carry no equivalent to the former Canadian fuel charge, though state and local taxes and riders still appear.

How to read a commercial gas bill, line by line

Once you know the structure, a methodical pass turns any gas bill into a defensible number. Work through it in this order:

1. Find the metered quantity and its unit (m3, Ccf, Mcf, or GJ) and confirm whether the reading is actual or estimated.
2. Note the billing conversion or heating value the utility used, since that governs every unit conversion downstream.
3. Separate the commodity or gas supply charge from the delivery, transportation, and distribution charges.
4. Split each remaining line into fixed versus variable, so you know which costs move with usage.
5. Identify rider, adjustment, and tax lines, and confirm the consumer carbon charge line reads zero on Canadian bills.
6. Normalize the total to one unit, such as dollars per GJ or per therm, for benchmarking across sites and periods.

How MartinAI helps

The hard part of gas billing is not the arithmetic, it is doing the arithmetic consistently across dozens of accounts, several utilities, and two countries, month after month, without transcription errors. MartinAI reads commercial gas bills, whatever unit they arrive in, and converts every account to a single validated basis using the heating values and conversion factors on the documents themselves. Commodity, transportation, delivery, fixed charges, riders, and taxes are separated automatically, so you can see the true variable cost per GJ or per therm for any site and compare it against the rest of the portfolio.

Because the data is validated at the point of capture, estimated reads, unit mismatches, and out-of-range charges surface as flags rather than as silent errors buried in a spreadsheet. That clean, whole-building series feeds cost analysis, rate reviews, benchmarking, and the combustion side of a Scope 1 emissions inventory without a second round of manual cleanup. The result is that your team spends its time interpreting gas costs instead of reconciling units.

Conclusion

A commercial gas bill is readable once you hold three ideas at once: the units are convertible if you use the utility's own heat content, the bill splits into a pass-through commodity and a regulated delivery, and each line is either fixed or variable. Add the current Canadian reality that the consumer carbon charge sits at zero since April 1, 2025, and the structural differences on US bills, and you can compare any gas account against any other. The remaining challenge is doing it reliably at scale, which is a data problem worth solving once rather than every billing cycle.