Natural Gas vs Propane Grill: Cost, Convenience and How to Choose

Natural gas and propane burn almost the same way at the grate. The difference is everything around the flame: where the fuel comes from, what it costs per hour, whether the grill can move, and what it takes to hook up. This guide compares the two honestly so you can decide before you buy, and explains what "convertible" really means on a Monument grill.

Quick Answer

Choose a natural gas grill if you already have a gas line to the patio or plan to add one, and the grill will stay in one spot. You will never run out of fuel mid-cook and pay roughly half as much per hour. Choose a propane grill if you rent, want to move the grill, or do not want to pay for a gas line. If you are not sure, a dual-fuel or convertible grill such as the Eminence 605 lets you start on propane and switch to natural gas later.

Natural Gas vs Propane Grill: Side-by-Side

Factor	Natural Gas Grill	Propane Grill
Fuel source	Piped from your home's gas line	20-lb refillable tank
Fuel cost per hour at 40,000 BTU	About $0.60 at $1.50 per therm	About $1.50 at $3.50 per gallon
Running out of fuel	Never	A 20-lb tank lasts 10 to 20 hours of cooking
Heat at the grate	Same as propane on a grill built for it	Same as natural gas on a grill built for it
Portability	Fixed to the hookup location	Moves anywhere
Installation	Gas line and quick-connect, usually by a licensed installer	Screw on the tank and go
Upfront cost	Grill plus gas line installation	Grill plus tank
Interchangeable?	No. Each fuel needs its own orifices and regulator. Switching requires a conversion kit or a dual-fuel model.

Fuel Cost: Natural Gas Is Cheaper Per Hour

Propane packs about 91,000 BTU into a gallon. A 20-lb tank holds about 4.7 gallons, or roughly 430,000 BTU. Natural gas is billed by the therm, which is 100,000 BTU. At typical US prices of around $3.50 per gallon for propane and $1.50 per therm for residential natural gas, propane costs about $3.80 per 100,000 BTU and natural gas about $1.50. Natural gas is less than half the price for the same heat.

What that means at the grill: a four-burner running at 40,000 BTU for an hour costs about $1.50 on propane and about $0.60 on natural gas. If you grill twice a week through the season, natural gas saves you around $50 to $100 a year. That is real money, but it is not enough on its own to justify a gas line. Convenience is the bigger reason.

Convenience: The Tank Problem

Every propane owner has run out of gas with guests waiting. A natural gas grill removes that problem entirely. There is no tank to refill, weigh or exchange, and no cold-weather pressure drop from a half-empty cylinder. Our cold-weather grilling guide explains why propane grills struggle to reach temperature in winter.

Propane wins on flexibility. You can roll the grill to the other side of the deck, take it to a second home, or bring a compact model on a trip. If you rent or expect to move in the next few years, propane avoids paying for a gas line you will leave behind.

Heat and Performance: No Real Difference

Propane carries more energy per cubic foot than natural gas, so natural gas grills use larger orifices to deliver the same BTU rating. A grill built for natural gas performs the same as the propane version of the same model. What you should never do is run a propane grill on natural gas or the reverse without converting it. The flames will be too small or dangerously large, and the burners will not work as designed.

Installation: What a Natural Gas Hookup Involves

• A gas line to the patio. If your home has natural gas for heating or cooking, a licensed installer can run a line outdoors and add a shutoff valve and quick-connect fitting. Cost depends on distance from the meter and local code.
• A natural gas regulator and hose. Natural gas grills ship with or require a regulator matched to the line pressure. Monument sells a natural gas regulator as a replacement part for specific models (the listing on 2026-09-12 names 77352NG). Check the fitment on the product page against your model before ordering.
• A leak check. Before the first cook, test every connection with soapy water. Here is how to perform a gas leak test.

Once installed, the grill lives at the hookup. Plan the location for wind, distance from the house and space for side tables before the line goes in.

Can You Convert a Propane Grill to Natural Gas?

Only if the manufacturer offers a conversion kit for that model. Conversion changes the orifices, the regulator and sometimes the valves, so it is not a universal adapter. Monument offers natural gas conversion kits for specific grills, and our step-by-step natural gas conversion kit assembly guide shows exactly what the job involves. If your grill is not on the compatible list, do not attempt a conversion with generic parts.

The simpler path is to buy a grill designed for both fuels. The natural gas convertible grills collection lists Monument models that can run on either supply, and the flagship Eminence 605 supports natural gas and propane out of the box with 66,000 BTU across six main burners (89,000 BTU including the rear infrared and side sear). Read more in our closer look at natural gas grills and the Eminence 605.

Which Should You Choose?

Natural gas makes sense if:

• Your home already has natural gas service.
• You own the home and plan to stay.
• The grill has a permanent spot on a patio or outdoor kitchen.
• You grill often enough that refilling tanks is a real chore.

Browse natural gas grills ready to connect to a home line.

Propane makes sense if:

• You rent, or you are not ready to pay for a gas line.
• You want to move the grill around the yard or take it with you.
• You grill a few times a month, so a tank lasts most of a season.
• You want the widest choice of models and sizes.

See every size from two-burner to six-burner in the gas grill collection. Our propane tank guide covers tank sizes, refills and how to check the level.

Not sure? Buy convertible.

A convertible grill costs little or nothing extra and keeps both options open. Start on propane today, add a gas line next year, and swap the supply without replacing the grill.

Frequently Asked Questions

Does natural gas or propane grill hotter?

Neither, on a grill built for that fuel. BTU ratings are set by the burner and orifice design. Propane has more energy per cubic foot, so natural gas grills simply flow more gas to reach the same output.

Is a natural gas grill cheaper to run?

Yes. At typical US prices natural gas costs less than half as much per BTU as propane. Expect to save roughly $50 to $100 per year if you grill twice a week through the season.

Can I use a propane tank on a natural gas grill?

No. The orifices and regulator are different. Connecting propane to a natural gas grill produces oversized flames and is a fire hazard. Use a conversion kit designed for your model or buy a dual-fuel grill.

How long does a 20-lb propane tank last?

About 430,000 BTU of energy. On a 40,000 BTU grill with every burner on high, that is roughly 10 hours. With two burners on medium, closer to 20 hours.

Do natural gas grills need a professional installer?

Running a new gas line almost always requires a licensed installer and a permit under local code. Connecting the grill to an existing quick-connect fitting is a simple job you can do yourself, followed by a leak test.

The Bottom Line

Natural gas is the better fuel for a grill that stays put at a home with gas service: cheaper per hour, never empty, no tanks. Propane is the better fuel for everyone else: no installation, full portability, and the widest range of grills. If you can see yourself wanting both, a convertible model like the Eminence 605 is the safe choice.