Propane
Propane patio heaters, with the cylinder arithmetic
The right choice for an open patio, and the fuel whose real cost nobody publishes. Four picks, and the division that tells you how many evenings a cylinder buys.
For an open patio, a 46,000 to 48,000 BTU propane tower is the most heat per dollar available. A 20 lb cylinder holds about 431,000 BTU, so at 48,000 BTU/h it runs for roughly nine hours — two or three evenings, not a season. That division is the fact most propane buyers meet by surprise.
Why propane still wins outdoors
The case for propane is a wiring case. A standard U.S. 120-volt branch circuit at 15 amps, derated to 80 percent for a continuous load, delivers about 1,440 watts. That is roughly 4,900 BTU per hour, and it is a ceiling no manufacturer can sell past. A propane tower carries its own energy supply, and 48,000 BTU/h is about ten times what your outlet can do.
On an open patio, where warmed air rises and leaves and has to be continuously replaced, that factor of ten is the whole argument. Nothing electric competes on an open patio unless it is hardwired at 240 volts, which is an electrician's project rather than a purchase.
The cylinder question, answered with the division
The single most-searched propane question is how long a cylinder lasts, and the honest answer is a calculation rather than a range. A nominal 20 lb cylinder holds 20 pounds of propane. Propane weighs 4.24 pounds per gallon, so that is 4.72 gallons. A gallon carries 91,420 BTU at higher heating value, the same basis appliance ratings use. So the cylinder holds about 431,000 BTU. Divide by the burn rate.
| Burn rate | 15 lb cylinder | 20 lb cylinder | 30 lb cylinder | 40 lb cylinder |
|---|---|---|---|---|
| 11,000 BTU/h | 29.4 h | 39.2 h | 58.8 h | 78.4 h |
| 40,000 BTU/h | 8.1 h | 10.8 h | 16.2 h | 21.6 h |
| 46,000 BTU/h | 7.0 h | 9.4 h | 14.1 h | 18.7 h |
| 48,000 BTU/h | 6.7 h | 9.0 h | 13.5 h | 18.0 h |
| 50,000 BTU/h | 6.5 h | 8.6 h | 12.9 h | 17.2 h |
Cylinder energy = pounds ÷ 4.24 lb per gallon x 91,420 BTU per gallon, divided by the burn rate. A 20 lb cylinder therefore holds 4.7 gallons and 431,226 BTU. Full output only — turn it down and every figure here stretches proportionally.
Two things follow. First, a full-output tower is a two-or-three-evening proposition per cylinder, which surprises almost everyone. Second, turning it down is the only lever that meaningfully changes that, and it changes it proportionally — half output really is double the evenings. The full runtime page covers the 15, 30 and 40 lb cases too.
Quick picks
Ranked for fit, not for hype. Output is the maker’s published figure; reach is computed from it or from the maker’s own radius claim, and the table says which. Tap a row for the full write-up, or go straight to the listing.
| # | Product | Best for | Output | Reach | Price |
|---|---|---|---|---|---|
| 1 | Amazon BasicsNo photo Amazon Basics 46kOne of the very few towers whose maker publishes a coverage radius rather than a vague area, and the 9 ft figure survives the arithmetic. That alone puts it ahead of most of the field. | The published-radius honesty test | 46,000 BTU | 254 sq ft claimed | Check price on Amazon |
| 2 | AZ Patio HeatersNo photo Hiland HLDS01The mushroom tower the whole category is a copy of. 48,000 BTU is enough for a genuinely open patio, and the parts are the easiest in the category to replace when something eventually fails. | A full open patio | 48,000 BTU | 2,400 sq ft | Check price on Amazon |
| 3 | EAST OAKNo photo EAST OAK pyramidThe pyramid is the best-looking heater in the category and the least efficient way to spend 48,000 BTU, because the flame column throws most of its output straight up. Buy it knowing that trade. | Looking good while heating less | 48,000 BTU | 2,400 sq ft | Check price on Amazon |
| 4 | AZ Patio HeatersNo photo Hiland tabletop11,000 BTU heats a table, not a patio, and being clear about that is the whole point. For a bistro table on a balcony it is the right size and nothing bigger fits. | One table, four people | 11,000 BTU | 550 sq ft | Check price on Amazon |
Reach marked “claimed” is the maker’s own published figure. Reach without that label is ours, computed from published output at 20 BTU per square foot for an open patio. Neither is a measurement we took.
Top pick · The published-radius honesty test
Amazon Basics 46,000 BTU Outdoor Propane Patio Heater
One of the very few towers whose maker publishes a coverage radius rather than a vague area, and the 9 ft figure survives the arithmetic. That alone puts it ahead of most of the field.
- Fuel
- Propane
- Output
- 46,000 BTU/h
- Reach (claimed)
- 254 sq ft · 9.0 ft radius
- Cost per hour
- $1.35
What works
- A published 9 ft radius is a 254 sq ft circle, and 46,000 BTU is far more than that area needs — a claim on the conservative side of its own specification, which is rare here
- The water-fill base box is a real anti-tip measure, not a sticker: filled, it is the difference between a windy evening and a repair bill
- One-touch ignition and a chain for the cylinder are both small things the cheap clones drop
What does not
- The listing does not name a safety certifying body, only the tilt valve, so we cannot tell you it is CSA listed
- 91 in tall with an open flame: the same wind exposure as every other tower of this shape
- The water box has to be emptied before a freeze or it splits
| Published specification | |
|---|---|
| Rated input | 46,000 BTU/h |
| Published reach | 9 ft radius |
| Dimensions | 32.1" L x 32.1" W x 91.3" H |
| Fuel | 20 lb propane cylinder, not included |
| Safety | Tilt auto-shutoff valve; chain to secure the cylinder |
| Base | Water-fill box for ballast, wheel kit included |
| Maker’s coverage claim | 9.0 ft radius, which is 254 sq ft |
| Safety listing | Tilt auto-shutoff valve; the listing does not name a certifying body |
Who it is for
An open patio where you want the largest honest circle of warmth per dollar and are happy to handle cylinders.
What it is not for
Anywhere enclosed, and anywhere the base cannot be filled with water — an empty ballast box makes this a tall, light, tippy object.
Sources for this entry
2 · A full open patio
Hiland / AZ Patio Heaters HLDS01-CG 87 in Propane Patio Heater
The mushroom tower the whole category is a copy of. 48,000 BTU is enough for a genuinely open patio, and the parts are the easiest in the category to replace when something eventually fails.
- Fuel
- Propane
- Output
- 48,000 BTU/h
- Reach (computed)
- 2,400 sq ft · 27.6 ft radius
- Cost per hour
- $1.40
What works
- 48,000 BTU is real output — on our sizing arithmetic that is a 2,400 sq ft open patio at the rule-of-thumb rate, so it is never the unit that is undersized
- Every wear part on this platform is a stocked commodity: thermocouples, control valves, dump switches and reflectors are all available separately
- The weight bladder in the base is the single most useful anti-tip feature in the category and most rivals leave it out
What does not
- An 87 in open-flame tower is the worst possible shape in wind — this is the unit our wind guide exists for
- The maker does not publish a coverage radius, so the reach figure we show is ours, computed rather than quoted
- Full output burns a 20 lb cylinder in well under a night. See the runtime arithmetic
| Published specification | |
|---|---|
| Rated input | 48,000 BTU/h |
| Height | 87 in |
| Fuel | 20 lb propane cylinder, not included |
| Reflector | 33 in aluminum heat shield |
| Safety | Anti-tilt cutoff and thermocouple flame-failure cutoff |
| Extras | Wheels, integrated table, weight bladder for the base |
| Maker’s coverage claim | None published — the reach figure above is ours |
| Safety listing | CSA certified per the maker's product literature |
Who it is for
An open patio with no roof, where you need volume of heat and can accept swapping cylinders. Also the right answer if you want a unit whose parts you can still buy in five years.
What it is not for
A screened porch, a garage, or anywhere without open sky above it. It is an open-flame combustion appliance and needs genuine outdoor ventilation.
3 · Looking good while heating less
EAST OAK 48,000 BTU Pyramid Patio Heater (2025)
The pyramid is the best-looking heater in the category and the least efficient way to spend 48,000 BTU, because the flame column throws most of its output straight up. Buy it knowing that trade.
- Fuel
- Propane
- Output
- 48,000 BTU/h
- Reach (computed)
- 2,400 sq ft · 27.6 ft radius
- Cost per hour
- $1.40
What works
- The four anchor stakes are the reason to pick this over most pyramids — they are the correct answer to a heater blowing over and they come in the box
- A 45-degree tilt cutoff is a more forgiving threshold than the twitchy switches that plague this shape
- The glass tube is a stocked replacement part, so a cracked one is a repair rather than a write-off
What does not
- A pyramid is a chimney. The visible flame column is beautiful and it sends heat vertically; a mushroom reflector at the same BTU puts more of it on people
- Tall glass tubes crack. Ours is not a durability test, but the existence of a whole replacement-tube market is its own data point
- The maker publishes no coverage figure at all, so the reach column here is entirely our arithmetic
| Published specification | |
|---|---|
| Rated input | 48,000 BTU/h |
| Flame tube | 4.7 in diameter quartz glass |
| Ignition | One-button, quoted at about 5 seconds |
| Safety | Cutoff at 45 degrees of tilt; instant gas shutoff on flame loss |
| Fuel | 20 lb propane cylinder, not included |
| Extras | Two rollers, four anchor stakes |
| Maker’s coverage claim | None published — the reach figure above is ours |
| Safety listing | Triple protection system: 45-degree anti-tip cutoff plus flame-failure cutoff |
Who it is for
Someone who wants the heater to be part of the evening rather than a utility object, on an open patio, and who has read the trade-off above and accepted it.
What it is not for
Getting the most warmth per dollar, or any covered space — a 7-foot flame column under a roof is the exact scenario the [clearance rules](/spaces/safety) exist for.
Sources for this entry
4 · One table, four people
Hiland HLDS032-BBS Tabletop Propane Patio Heater
11,000 BTU heats a table, not a patio, and being clear about that is the whole point. For a bistro table on a balcony it is the right size and nothing bigger fits.
- Fuel
- Propane
- Output
- 11,000 BTU/h
- Reach (computed)
- 550 sq ft · 13.2 ft radius
- Cost per hour
- $0.32
What works
- Runs off a 1 lb canister, which makes it the only heater here you can carry out to a table and back with one hand
- 11,000 BTU is honest for the job: our reach arithmetic puts that at roughly a table's worth of warmth, and the unit does not pretend otherwise
- A burner screen guard on a table-height heater is a genuine safety feature, not a spec-sheet line
What does not
- 1 lb canisters are the most expensive propane per BTU you can buy — get the 20 lb adapter hose if you use it regularly
- At 38 in on a table, this puts an open flame at seated head height. Placement matters more than with any other unit here
- It will not touch an open patio. Anyone expecting a room-scale effect will be disappointed
| Published specification | |
|---|---|
| Rated input | 11,000 BTU/h, adjustable |
| Height | 38 in |
| Fuel | 1 lb canister or 20 lb cylinder with an adapter hose |
| Safety | Thermocouple, anti-tilt device, burner screen guard |
| Stability | Weight plate in the base |
| Maker’s coverage claim | None published — the reach figure above is ours |
| Safety listing | Thermocouple flame-failure cutoff and anti-tilt device per the listing |
Who it is for
A balcony, a bistro table, or a second heater that warms hands at the table while a tower does the space.
What it is not for
Heating an area. And never indoors, on a covered porch with a low ceiling, or anywhere a tablecloth can reach it.
Sources for this entry
What we would skip
A list with no losers is a list nobody edited. These are the choices we would actively steer you away from, and why.
Buying the highest BTU number you can find
48,000 BTU covers 2,400 sq ft on the standard rule. Almost nobody has a 2,400 sq ft patio. Past about 46,000 BTU you are buying fuel consumption, not comfort — and every extra thousand BTU shortens the cylinder. The runtime table makes the trade obvious.
A propane tower for any covered space
Propane heaters are open-combustion appliances. They consume oxygen and produce flue gas, and every manual in the category says outdoor use only. Under a roof there is also the clearance problem: 36 inches above an 87-inch tower needs a ceiling over ten feet. The clearance figures are here.
1 lb canisters as a regular fuel source
Convenient for a couple of evenings a year, and the most expensive propane per BTU on the market by a wide margin. If a tabletop heater gets weekly use, buy the adapter hose and run it from a 20 lb cylinder.
What a propane heater costs to run
The prices every cost figure on this site uses
- Electricity: 18.34 cents per kWh. U.S. average residential retail price, June 2026. EIA, Electric Power Monthly, Table 5.6.A (residential, U.S. total).
- Propane: $2.674 per gallon. U.S. average residential price, week ending March 30, 2026. EIA, Weekly Heating Oil and Propane Prices (residential, U.S. average). That series only runs through the heating season, which is why the latest reading is a March one.
- Propane energy content: 91,420 BTU per gallon (higher heating value, the same basis appliance BTU ratings use). U.S. DOE Alternative Fuels Data Center, Fuel Properties Comparison.
- Conversion: 1 kWh = 3,412 BTU. Which is why a 1,500 W electric heater is a 5,118 BTU/h appliance, and why comparing it to a 48,000 BTU propane tower is not the comparison it looks like.
One caveat we would rather state than bury: the price above is the U.S. residential average for bulk-delivered propane. If you refill 20 lb cylinders at an exchange cage outside a supermarket, you are paying materially more per gallon than that, and the exchange cylinders are commonly filled to 15 pounds rather than 20. Treat every cost and runtime figure on this site as the optimistic end.
How we picked
- Rated input published by the maker. Every pick states its BTU/h. Runtime and cost per hour are computed from that figure, not quoted from anywhere.
- Parts availability weighed heavily. A propane heater is a gas appliance with consumable safety parts. A platform whose thermocouple and control valve you can still buy is worth more than a marginally better spec you cannot service.
- Anti-tip provision counted as a feature, not a footnote. A ballast reservoir or anchor stakes in the box is the difference between a windy night and a repair.
- Coverage claims quoted only where a maker publishes one — and checked against the output rather than repeated.
What we did not do
Everyone in this category says they tested twenty heaters. We have not tested any, and we say so. What we do instead: compile the published specs, compute the electrical and gas load from them, cite the maker’s own manual, and show the arithmetic so you can check it. The full method, including how to challenge a figure.
Common questions
How long does a 20 lb propane tank last on a patio heater?
About 9 hours at 48,000 BTU/h and about 9.4 at 46,000. The cylinder holds roughly 431,000 BTU (4.72 gallons at 91,420 BTU each), so runtime is that number divided by the burn rate. At half output it roughly doubles.
How much does it cost to run a propane patio heater?
About $1.40 an hour for a 48,000 BTU unit at the U.S. average residential propane price of $2.674 per gallon. A four-hour evening is around $5.60. Exchange-cage cylinders cost more per gallon than bulk propane, so treat that as a floor.
Can I use a 20 lb tank on a tabletop patio heater?
Usually yes, with an adapter hose, and it is much cheaper per BTU than 1 lb canisters. The Hiland tabletop unit is explicitly rated for either. Check your own model's manual before connecting anything.
Do propane patio heaters need ventilation?
Yes. They are open-combustion appliances that consume oxygen and produce flue gases including carbon monoxide. They are outdoor products and every manual says so. Under a roof with fully open sides is generally acceptable; a screened or largely enclosed space is not.
Sources
Read next
How long a propane cylinder actually lasts
The cylinder arithmetic in full: energy content, burn rate, and every size from 15 to 40 lb.
Electric vs propane patio heaters
Output, cost, coverage, wind and installation compared, with the arithmetic and picks for both answers.
How to keep a propane heater lit
The flame-failure sequence explained, and the five things that keep a burner alight in a breeze.
The best patio heaters, sorted by the patio
Six heaters covering every real patio case, with published output, computed reach and cost per hour.
Patio heater safety, with the published numbers
Published clearance figures, the ventilation rule, and where each heater type must never go.