Gas Bill Calculator

Enter your monthly gas usage and choose city gas or propane (LP gas) to estimate your monthly gas bill, based on a base fee plus usage-rate pricing structure. Includes an explanation of why city gas and propane prices differ.

Tips

  • Enter the "usage (m³)" figure shown on your meter reading slip or gas provider's online account to get an estimate close to your actual bill.
  • Gas usage often rises to 2-3 times the summer level in winter due to water heating and space heating, so bills can swing widely by month. Recalculating for each season helps you get a better sense of your annual costs.
  • If you're considering switching from propane to city gas, you'll need to check with a gas company whether your area has city gas pipeline infrastructure in place.
  • Unit prices for propane vary widely between providers even for the same gas. Compare the unit price on your current meter reading slip with this tool's reference price to check whether you're paying above average.

Frequently Asked Questions

City gas is delivered through an underground pipeline network, which is highly cost-efficient thanks to large-scale supply. Propane, on the other hand, must be delivered to each household by truck in cylinders, adding delivery costs, inventory management costs, and the cost of a lower customer density per supplier. Propane is also unregulated, so providers can set prices freely, which is another reason unit prices tend to stay high.

Propane has roughly double or more the heating value per unit volume compared to city gas. This means actual usage in cubic meters tends to be lower with propane, but since the price gap is larger than the usage gap, propane still typically works out more expensive overall.

Since propane is priced freely by each provider, rates can sometimes be lowered by negotiating with your provider or switching to another company. This can be harder for renters, since the contract is often tied to the landlord or management company, but homeowners can benefit from getting quotes from multiple providers.

Small habits add up: avoid setting your water heater temperature higher than necessary, dry pots before putting them on the stove, and close the bathtub lid promptly to retain heat. Replacing your water heater or gas stove with an energy-efficient model can also lead to savings over the medium to long term.
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Side Note — What Separates City Gas from Propane: Pipeline Infrastructure

The reason city gas and propane coexist in Japan comes down to differences in underground gas pipeline infrastructure. Urban areas have had pipelines built out gradually since the postwar era, but in mountainous regions and some newer residential developments where laying pipelines isn't cost-effective, propane remains the norm. Once the fixed infrastructure of a pipeline is built, city gas providers can enjoy economies of scale from large-volume supply for a long time, whereas propane inherently carries an ongoing variable cost: delivering cylinders to each household.

There's also a fundamental difference in pricing structure. City gas functions much like a public utility, with providers setting rates through a formal filing process with the Ministry of Economy, Trade and Industry, resulting in relatively unified rates within a region. Propane, by contrast, is priced freely, so it's not unusual for unit prices to differ by tens of yen per cubic meter between providers even in the same area — and consumers who don't compare providers may not realize they're on an overpriced contract.

In recent years, propane has also been re-evaluated from a disaster-preparedness perspective. Large-scale pipeline networks for city gas can take a long time to restore if damaged by an earthquake, whereas propane's distributed infrastructure — an independent cylinder at each household — means supply disruptions tend to stay localized. In fact, households using propane have been reported to resume cooking and hot water use sooner after past major earthquakes.