Maximum output
High BTU patio heaters, and when the number stops helping
46,000, 48,000, 50,000. The differences between them are smaller than the marketing suggests, and past a point you are buying fuel consumption rather than comfort.
The highest-output patio heaters sit at 46,000 to 48,000 BTU/h, and the gap between them is about four percent — not a difference anyone can feel. A 48,000 BTU unit covers about 2,400 sq ft on the standard rule and empties a 20 lb cylinder in about nine hours.
What these numbers actually buy
48,000 BTU/h at the standard 20 BTU per square foot rule corresponds to 2,400 square feet of open patio. Very few homes have a patio a quarter of that size. So for almost every domestic buyer, the top of this category is not a capability question at all — you are already well past what the space needs at 46,000, at 40,000, and often at half that.
What the high rating genuinely gives you is headroom on a cold, exposed night, and the ability to run at a lower setting most of the time. Both are real. What it does not give you is a proportionally warmer patio, because the coverage was never the constraint.
The trade nobody puts on the box
Rated input is fuel consumed per hour, so a higher rating is by definition a shorter cylinder. The two are the same fact.
| Burn rate | 15 lb cylinder | 20 lb cylinder | 30 lb cylinder | 40 lb cylinder |
|---|---|---|---|---|
| 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 |
| 58,000 BTU/h | 5.6 h | 7.4 h | 11.2 h | 14.9 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.
Read across the 20 lb row: 40,000 BTU/h gives you about 10.8 hours; 58,000 gives about 7.4. That is a third less runtime for a rating you probably did not need. If you use a heater regularly, that difference shows up as more trips to the refill station over a season than any amount of extra warmth justifies.
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 | 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 |
| 2 | 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 |
| 3 | 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 |
| 4 | Outland LivingNo photo Outland Firebowl 89358,000 BTU is more rated input than any patio heater in this registry, in a 19 in bowl you can carry. The catch is that an open bowl throws most of that straight up. | The highest published output here | 58,000 BTU | 2,900 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 · 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.
2 · 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
3 · 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
4 · The highest published output here
Outland Firebowl 893 Deluxe Portable Propane Fire Pit, 19 in
58,000 BTU is more rated input than any patio heater in this registry, in a 19 in bowl you can carry. The catch is that an open bowl throws most of that straight up.
- Fuel
- Propane
- Output
- 58,000 BTU/h
- Reach (computed)
- 2,900 sq ft · 30.4 ft radius
- Cost per hour
- $1.70
What works
- 58,000 BTU with no wood, no smoke and no ash — it is on in ten seconds and off in one
- Propane means it is legal in most fire-ban conditions where wood is not, though check your own county before assuming
- Portable enough to take camping, which no other heat source here manages
What does not
- An open bowl is a chimney. The rated input is the highest here and the useful radiant fraction is among the lowest — do not read 58,000 BTU as 58,000 BTU of warmth on people
- At full output a 20 lb cylinder empties fast. The runtime table has the exact figure
- The hose runs across the ground to the cylinder, which is a trip hazard and a design compromise the fire tables avoid
| Published specification | |
|---|---|
| Rated input | 58,000 BTU/h |
| Diameter | 19 in |
| Fuel | 20 lb cylinder via the included hose and regulator |
| Included | Cover and carry kit on the Deluxe |
| Fill | Lava rock included |
| Maker’s coverage claim | None published — the reach figure above is ours |
| Safety listing | CSA certified per the maker's published product data |
Who it is for
Somewhere that needs instant, smokeless flame on demand, including places where a wood fire is not permitted.
What it is not for
Efficient heating, decks without a [heat barrier](/fire-pits/deck-safe), and anywhere with anything overhead.
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.
Choosing between 46,000 and 48,000 BTU
It is a four percent difference. On the standard rule that is 2,300 sq ft of coverage versus 2,400, and nobody has a patio where that matters. Choose on build, stability, parts availability and weather rating instead — those differences are real.
High BTU on a small patio
A 150 sq ft patio needs about 3,000 BTU/h in still air. A 48,000 BTU tower is sixteen times that. You will run it on low, which works, and you will still empty cylinders faster than a smaller unit would. Size it first.
Reading a fire pit's BTU as heater BTU
A 58,000 BTU open bowl has the highest rating on this page and is not the warmest thing on it for people sitting around a patio. An open bowl sends most of its output vertically. The comparison is here.
When high BTU genuinely is the right call
- A large, genuinely open patio — 400 sq ft and up with no roof, where warmed air leaves continuously.
- An exposed position. On our model exposure raises the requirement by about 40 percent, and headroom is the honest response when the wind cannot be blocked.
- Commercial or semi-commercial use — a terrace where people arrive cold and expect it to be warm immediately rather than in twenty minutes.
- A cold climate, where the temperature difference the heater is working against is genuinely large.
What it costs at these rates
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.
Electric, per hour
| Rated power | Per hour | 4-hour evening | Per month, 4 h a night |
|---|---|---|---|
| 750 W | $0.14 | $0.55 | $16.51 |
| 900 W | $0.17 | $0.66 | $19.81 |
| 1,200 W | $0.22 | $0.88 | $26.41 |
| 1,500 W | $0.28 | $1.10 | $33.01 |
| 2,000 W | $0.37 | $1.47 | $44.02 |
| 3,000 W | $0.55 | $2.20 | $66.02 |
At 18.34 cents per kWh (June 2026 U.S. residential average). Substitute your own rate: it is on your bill, and the arithmetic is watts ÷ 1000 x hours x rate.
Propane, per hour
| Rated input | Per hour | 4-hour evening | Per month, 4 h a night |
|---|---|---|---|
| 11,000 BTU/h | $0.32 | $1.29 | $38.61 |
| 40,000 BTU/h | $1.17 | $4.68 | $140.40 |
| 46,000 BTU/h | $1.35 | $5.38 | $161.46 |
| 48,000 BTU/h | $1.40 | $5.62 | $168.48 |
| 50,000 BTU/h | $1.46 | $5.85 | $175.50 |
At $2.674 per gallon (week ending March 30, 2026 U.S. residential average) and 91,420 BTU per gallon. Exchange-cage cylinders cost materially more per gallon than a bulk refill, so treat this as the floor.
At $2.674 a gallon, 48,000 BTU/h is about $1.40 an hour and $5.61 for a four-hour evening. Over a five-month season at four hours a night that is around $842, which is more than most of these heaters cost to buy. That is the number worth knowing before deciding output is free.
How we picked
- Rated input above 45,000 BTU/h, published by the maker, or the unit is not here.
- Coverage checked against output, not repeated from marketing. A high rating with a modest published radius is a conservative claim and we say so.
- Runtime computed for every unit, because a high burn rate is also a short cylinder and that trade is the point of the page.
- Heat direction considered. A 58,000 BTU fire bowl outranks every heater here on paper and sends much of it upward, which we state on its card rather than letting the number stand alone.
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 many square feet does a 48,000 BTU patio heater cover?
About 2,400 square feet on the standard 20 BTU per square foot rule for an open patio. In practice the useful warm zone is far smaller, because coverage falls off with distance and much of the output warms air that rises away. The published radius on units that give one is typically 9 feet, which is 254 square feet.
Is 50,000 BTU better than 48,000 BTU?
By four percent, which nobody can feel, and at the cost of a proportionally shorter cylinder. Choose between units of this class on stability, weather rating, parts availability and build rather than on the rating.
What is the highest BTU patio heater?
Domestic patio heaters top out around 48,000 BTU/h. Propane fire bowls go higher — 58,000 BTU is common — but an open bowl sends much of its output upward, so a higher rating there does not mean a warmer seating area.
Does a higher BTU heater use more propane?
Yes, in direct proportion, because rated BTU is fuel consumed per hour. A 58,000 BTU unit empties a 20 lb cylinder in about 7.4 hours against about 9 for a 48,000 BTU one.
Read next
Patio heater BTU calculator
Your patio's BTU requirement with every multiplication shown, plus why the published rules disagree.
How long a propane cylinder actually lasts
The cylinder arithmetic in full: energy content, burn rate, and every size from 15 to 40 lb.
Propane patio heaters, with the cylinder arithmetic
Four propane heaters compared on published BTU, computed reach and real cylinder runtime.
The cheapest patio heaters to run
Which heaters cost least per evening at published energy prices, and the change that beats all of them.