Safety · Electrical
It draws 12.5 amps. The circuit allows 12. This is the calculation almost no heater article performs, and it changes where you plug in.
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A 1,500 W heater draws 12.5 amps at 120 V. A 15 A branch circuit supports 12 A of continuous load under the 125% sizing rule, so a 1,500 W heater technically exceeds it. It will usually run without tripping, but it should not share the circuit with anything else significant.
Step one — the draw. Amps equal watts divided by volts. 1,500 ÷ 120 = 12.5 A. That is a fixed property of the heater and it does not vary.
Step two — the allowance. Electrical code treats a load that operates for three hours or more as continuous, and requires the branch circuit conductors and the overcurrent device to be rated at not less than 125% of it (NFPA 70, Article 210.19(A)(1) and 210.20(A)). Dividing through: a continuous load may occupy at most 80% of the breaker rating.
| Heater | Draw at 120 V | 15 A circuit (12 A limit) | 20 A circuit (16 A limit) |
|---|---|---|---|
| 750 W | 6.3 A | Fits | Fits |
| 900 W | 7.5 A | Fits | Fits |
| 1,200 W | 10.0 A | Fits | Fits |
| 1,500 W | 12.5 A | Over the limit | Fits |
| Maximum continuous | — | 12 A = 1,440 W | 16 A = 1,920 W |
Draw computed as watts / 120 V. The continuous limit is 80% of the breaker rating, which follows from the NEC's requirement to size a circuit at 125% of a continuous load (NFPA 70, 210.19(A)(1) and 210.20(A)).
A space heater run for an evening is unambiguously a continuous load — it is the textbook example. So the honest conclusion is the one at the top of this page: 12.5 A does not fit within a 15 A circuit's 12 A continuous allowance.
Because a breaker is a thermal-magnetic device, not a precise gate. A 15 A breaker does not trip at 15.0 A — it trips on a time-current curve, carrying a modest overload for a long time before opening. At 12.5 A it will not trip at all, ever.
The 80% rule is not about the breaker tripping. It is about sustained heat in the conductors, the terminations and the breaker itself over years of use. Continuous loads at the full breaker rating cause connections to warm, warm connections oxidize, oxidized connections have higher resistance, and higher resistance produces more heat. The failure this rule prevents is a slow one at a terminal screw, not a dramatic one.
In most houses, the outlets in a single bedroom are on one circuit shared with an adjacent room or hallway. That is fine for a heater plus lamps and chargers. It is not fine for a heater plus a second heater, a window air conditioner, a microwave or a workshop tool.
Fitting a bigger breaker. The breaker protects the wire, not the appliance. Putting a 20 A breaker on 14-gauge wiring rated for 15 A removes the protection and leaves the wire to be the fuse. This is dangerous and it is a code violation.
Using an extension cord or a power strip to reach another outlet. A power strip does not change which circuit you are on, and a cord adds resistance and a connector exactly where a continuous 12.5 A load will find it. Why this is the wrong tool.
Ranked for fit, not for hype. Coverage and current draw are computed from each unit’s published wattage. Tap a row for the full write-up, or go straight to the listing.
| # | Product | Best for | Covers | Draw | Price |
|---|---|---|---|---|---|
| 1 | Dr. Infrared HeaterNo photo Dr Infrared DR-968The one listing in this category that publishes its amp draw and its noise level, which is exactly the arithmetic everyone else leaves you to do — 12.5 A and 39 dB, both stated. | The published numbers | 150 sq ft | 12.5 A | Check price on Amazon |
| 2 | LaskoNo photo Lasko 754200The 900 W low setting is the whole point: it is the rare listing that publishes both settings, so you can compute what the cheap mode actually costs instead of guessing. | One person at one desk | 150 sq ft | 12.5 A | Check price on Amazon |
Coverage computed at 10 W/sq ft, average insulation, 8 ft ceiling. Draw computed as watts ÷ volts. Neither figure is a manufacturer claim.
Top pick · The published numbers
The one listing in this category that publishes its amp draw and its noise level, which is exactly the arithmetic everyone else leaves you to do — 12.5 A and 39 dB, both stated.
| Published specification | |
|---|---|
| Rated power | 1,500 W at 120 V |
| Current draw | 12.5 A (published) |
| Noise | 39 dB (published) |
| Element | Infrared quartz tube plus PTC |
| Thermostat | Electronic, 50–85°F |
| Other | 12-hour auto-off timer, IR remote, caster wheels, 19 lb |
| Heat type | Infrared quartz |
| Maker’s coverage claim | None published — the coverage figure above is ours |
| Safety listing | No listing mark published in the listing text; check the cabinet's rating plate for the UL or ETL mark. |
Who it is for
A reader who wants to compute the load rather than trust a claim: the published amp draw and decibel figure make it the easiest unit on this site to check.
What it is not for
A 15 A circuit shared with anything else, and not a small room where a 19 lb cabinet on wheels is in the way.
2 · One person at one desk
The 900 W low setting is the whole point: it is the rare listing that publishes both settings, so you can compute what the cheap mode actually costs instead of guessing.
| Published specification | |
|---|---|
| Rated power | 1,500 W high / 900 W low, at 120 V |
| Maker's coverage claim | None published — sold as a desktop heater |
| Thermostat | Adjustable, 11 settings |
| Size | 9.2" tall |
| Other modes | Fan-only |
| Heat type | Ceramic (PTC) |
| Maker’s coverage claim | None published — the coverage figure above is ours |
| Safety listing | No listing mark published in the listing text; check the rating plate for UL or ETL. |
Who it is for
A desk, a small office, a dorm room — somewhere you want heat on a person rather than in a room.
What it is not for
Overnight or unattended use, and not a nursery. Without a published tip-over cutoff it does not belong on carpet next to a bed.
Sources for this entry
12.5 amps at 120 volts. The arithmetic is amps = watts ÷ volts, so 1,500 ÷ 120 = 12.5. At 240 V a 1,500 W load would draw 6.25 A, but plug-in heaters in the U.S. are 120 V appliances.
It will run without tripping, but 12.5 A exceeds the 12 A continuous limit that the 125% sizing rule gives a 15 A circuit. Do not share that circuit with other significant loads, and prefer a lower setting or a dedicated circuit.
A 20 A circuit gives a 16 A continuous allowance, which accommodates a 1,500 W heater with genuine headroom. Never fit a larger breaker to existing wiring — the breaker protects the wire, and the wire gauge sets the limit.
Almost always because something else substantial is on the same circuit. A 12.5 A heater plus a few amps of anything else exceeds 15 A. Find out which outlets share the breaker, and move one of the loads.
Where the 750 / 1000 / 1500 W tiers come from, and why 1500 W is a hard ceiling on a U.S. outlet.
Why 12.5 continuous amps through a cord is the wrong tool, and what to do when the outlet is too far.
Desk-side picks with a low setting, plus the circuit-load problem an office heater creates.
A two-car garage needs about 9,000 W. An outlet gives you 1,500. What to do instead.
200 sq ft wants 2,000 W and an outlet gives 1,500. The gap, and four ways to close it.
The only listing here publishing amps and decibels — 12.5 A and 39 dB, both stated.