How Long Does Propane Last on a Boat?

Running out of propane at the wrong moment is practically a boating tradition. It always happens when you’re halfway through cooking dinner, you’re anchored out, and there’s no quick run to the store.

The good news is you can avoid it. Once you understand your typical propane use on a boat (and how long a tank will last), it’s easy to plan refills, keep a backup, and stop getting surprised by an empty tank.

Here’s a simple rule of thumb for liveaboards and cruisers, plus a few easy ways to track what you have left.

Average Propane Use for Cruisers

A basic rule of thumb is 1 pound per person per week of full-time living.

That assumes:

• “Average” amounts of cooking and baking; few to no electrical appliances such as coffee makers or microwaves
• No particularly cold weather where you cook or bake for long periods to warm up the boat
• No propane refrigeration (with a small propane refrigerator, we used a little over 1 pound a day for two people)

The larger the number of people, the less per person you’re likely to use as cooking time isn’t perfectly proportional to the amount cooked. And single-handers may go through a bit more. But for most families, one pound per person per week is a good starting point.

Tank Size Considerations

Many boats use 20-pound tanks, but note that if you do a tank exchange at a store (common in the US), it’s generally only filled with 15 pounds. I get about 2-1/2 months from one of these and just over 3 months with a full 20-pound tank. Some boats use 10-pound tanks to make them easier to carry for refills or exchanges and I’ve seen a couple of boats (who have propane refrigeration, which I really don’t recommend) that have 40-pound tanks.

Whatever size tank you get, I strongly recommend having two so that you can swap tanks instantly when one becomes empty (they always go empty at the least convenient times). The spare tank needs to be kept where any leak will not drain into the boat.

Tracking Your Propane Use

We also had a gauge on the propane line, which helped us know when a tank was getting low. A gauge isn’t strictly necessary, but if I’m baking something like bread or a cake where having the tank go empty in the middle would cause funny results (and not just a delay), I’ll check the propane level before lighting the oven and change the tank if it’s virtually empty.

The gauges may not be perfectly accurate, but we’ve had very good luck with them being close to correct (note: some brands get much better reviews than others). Also, when we see the needle starting to drop, we double-check that the spare tank is, in fact, full. All it takes is one morning without coffee and you’ll never forget to check again!

• Gauge Master Propane Gauge on Amazon

Advice So You Don’t Run out of Propane on Your Cruising Boat

Other cruisers often have great tips of their own. Laney suggested one low-tech solution. Run boiling water down the side of the tank. Run you hands down the tank. Where it’s warm, there is no gas. It will feel cold where there is propane.

Pamela D, a member of the Boat Galley team, used a small luggage or fish scale (Amazon). It was a handheld doohickey with a spring. Subtract the tare weight printed on the side from the amount you measure to know how much is left. She also kept two tanks for her coastal cruising, an aluminum one she refilled and one she swapped out at the grocery store when refilling was not an option.

Jane H kept a basic backup on board–a 1-pound propane can she could attach to her regular propane. You wouldn’t want to rely on it, but it worked in a pinch.

Learn More

Living on a boat has a lot of little systems like this—propane, water, power, storage, and more. If you’d like a clear, practical head start, take a look at our online course The Basics of Living on a Boat.

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