Most home standby generators can run on either natural gas or propane. Which one you use usually isn't much of a choice: if you have natural gas service at the house, most people use it. If you don't, propane is the usual option. But the fuel does change what the install involves and what it costs. This guide covers the differences, with cited ranges and what homeowners on this site have reported.
The short version
- Natural gas: you need a gas line from your meter to the generator. The cost depends heavily on distance, and sometimes on whether your meter can supply enough gas.
- Propane: you need a tank and a line from the tank to the generator. If you already have a large enough tank, the cost can be modest. If not, the tank is a real line item.
Everything else on the quote, like the transfer switch, pad, permit and labor, is broadly similar for both.
Unit prices by fuel
HomeGuide lists unit-only prices by fuel for units from 2 to 24 kW: $3,000 – $6,000 (HomeGuide, accessed Nov 2026) for natural gas and $2,000 – $6,000 (HomeGuide, accessed Nov 2026) for liquid propane. In practice the same model is often sold for both fuels, so the unit price difference tends to be small compared with the fuel setup.
Natural gas: the gas line
A natural gas install means running pipe from your gas meter to wherever the generator will sit. HomeGuide lists gas line installation at $12 – $25 per foot (HomeGuide, accessed Nov 2026), and This Old House puts a natural gas line hookup at $15 – $20 per foot (This Old House, accessed Nov 2026).
What pushes it up:
- Distance. The farther the generator sits from the meter, the more pipe and labor.
- Trenching. HomeGuide notes complex jobs may require long trenches for gas pipes (HomeGuide, accessed Nov 2026).
- Meter capacity. A standby generator uses a lot of gas when it's running. Your installer and your gas utility will decide whether the existing meter is big enough. If it isn't, ask who handles the upgrade and what it costs.
Our gas line cost guide goes into more detail and shows what homeowners here paid by run length.
Propane: the tank
A propane generator needs a fuel tank. HomeGuide puts propane tanks at $400 – $1,800 (HomeGuide, accessed Nov 2026) on average. Questions to settle with your installer or propane supplier:
- Do you already have a tank, and is it big enough to run a generator through a long outage?
- Will the tank be bought or leased? Leasing changes the upfront cost and ties you to a supplier.
- Where will the tank sit, and how long is the line to the generator?
- Who handles the tank set and line: the generator installer or the propane company?
Tank sizing and placement rules come from your propane supplier, local codes and the generator maker. This site doesn't give advice on those; your licensed installer and supplier will.
Running costs are a separate question
This site tracks what it costs to get a generator installed, not what it costs to run. Fuel prices differ a lot by region and season, and propane has to be delivered and stored while natural gas comes through the meter. If running cost matters to your decision, ask your installer for an estimate based on your local fuel prices.
What homeowners on this site paid, by fuel
This table updates as reports are approved. A row shows numbers once it has at least three approved reports.
| Fuel (total installed) | Median | Reports |
|---|---|---|
| Natural gas | Collecting data | 0 |
| Propane | Collecting data | 0 |
From approved homeowner reports on this site. A row shows numbers once it has 3 or more reports.
To see figures for your area and fuel, look up your ZIP. If you have a quote in hand, the quote checker compares it with local installs of the same fuel.
Comparing quotes across fuels
If you're getting quotes for a house that could go either way, make sure each quote spells out the fuel side of the job:
- For natural gas: the run length and whether the full run is included, plus any meter work.
- For propane: whether a tank is included, bought or leased, and the line from tank to generator.
Without that, a propane quote can look cheaper or more expensive than a natural gas quote for reasons that have nothing to do with the generator. Our quote breakdown guide lists the other line items to check.
Questions that make fuel quotes comparable
If you have a choice of fuels, ask each installer to quote the same generator size on both, so the only difference is the fuel work. Then ask:
- For natural gas, how long is the run from the meter, and has anyone confirmed the meter and service can carry the extra load?
- For propane, what tank size do you recommend for the runtime I want, and is the tank bought or leased from a supplier?
- Who supplies, sets and fills the tank, and is the first fill in the quote?
- Does the quote include the regulator, the underground or above-ground line to the generator, and any tank pad?
- Which permits and inspections apply to each fuel here, and are they priced into the quote?
The answers usually explain most of the gap between a natural gas quote and a propane quote for the same house.
A note on safety
Gas and propane connections are work for licensed professionals. This site doesn't give installation, code or safety advice. Use a licensed installer and follow your local codes and permit requirements.
Share what you paid
If you've installed a natural gas or propane standby generator, report your cost. Mention the gas-line run length if you know it. That's what lets us show fuel-by-fuel numbers for your area.
Sources
- How Much Does a Whole House Generator Cost (2026), HomeGuide. Accessed Nov 3, 2026.
- How To Install an Automatic Standby Generator, This Old House. Accessed Nov 3, 2026.
- Homeowner figures: approved reports on GeneratorCostCheck. How the data works.