Energy

BTU/h to Watts

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BTU/h W
Formula

Multiply BTU/h by 0.293071

1 BTU equals 1055.06 joules (the precise IT-table value). 1 BTU per hour equals 1055.06 J ÷ 3600 s = 0.293071 W. ConvertBuddy assumes BTU/h when converting BTU to watts, since that is the rated specification on HVAC and combustion equipment. To convert raw BTU (energy, not rate) to joules instead, multiply by 1055.06. Energy and power are different physical quantities — confusing them gives nonsense results for sizing decisions.

About btu/h to watts

BTU and watts both relate to energy, but in different forms. A BTU (British Thermal Unit) is energy — the heat to raise one pound of water by one degree Fahrenheit. A watt is power — energy per unit time, specifically one joule per second.

The conversion most people search for is actually BTU per hour (BTU/h) to watts, which compares heating or cooling rates. Air conditioners, furnaces, gas grills, and water heaters all rate output in BTU/h in the US and in watts or kilowatts in metric markets.

1 BTU/h equals 0.293 watts. A 10,000 BTU/h window AC equals roughly 2.93 kW of cooling capacity.

Common conversions

BTU/h W
1000 BTU/h 293.1 W
2000 BTU/h 586.1 W
3000 BTU/h 879.2 W
5000 BTU/h 1465.4 W
6000 BTU/h 1758.4 W
8000 BTU/h 2344.6 W
9000 BTU/h 2637.6 W
10000 BTU/h 2930.7 W
12000 BTU/h 3516.9 W
15000 BTU/h 4396.1 W
18000 BTU/h 5275.3 W
24000 BTU/h 7033.7 W
36000 BTU/h 10550.6 W
48000 BTU/h 14067.4 W
60000 BTU/h 17584.3 W
Also: Watts to BTU/h

When you need this

Sizing an air conditioner

US window and portable AC units rate cooling in BTU/h. European mini-splits rate in watts or kW. Convert to compare the same model spec across regions or pick the right unit for a room calculated by either local sizing guide.

Comparing gas vs electric heaters

Gas heaters list output in BTU/h, electric heaters in watts. Convert to evaluate true output capacity, not just sticker spec, when deciding which to install for a given space.

Outdoor patio heater purchasing

Patio heaters in the US list 40,000-50,000 BTU/h. EU-sold equivalents list 12-15 kW. Convert to confirm the heater handles your patio area before buying internationally.

Pool heater sizing

Inground pool heaters rate 200,000-400,000 BTU/h. Heat pump alternatives rate in kW. Convert to compare operating cost across heater types using a single power unit.

Server-room HVAC planning

Server rack heat dissipation is given in watts (server PSU draw). HVAC capacity is sold in BTU/h or tons (12,000 BTU/h per ton). Convert to size the cooling solution against the heat load.

FAQ

How do I convert BTU to watts?

If you mean BTU/h (the typical equipment rating), multiply by 0.293. So 10,000 BTU/h = 2930 W = 2.93 kW. If you mean raw BTU energy (rare in everyday use), multiply by 1055 to get joules.

What is 1 BTU in watts?

1 BTU per hour equals 0.293 watts. Conversely 1 watt equals 3.412 BTU/h. The factors come from 1 BTU = 1055.06 J spread across 3600 seconds per hour.

How many watts is a 10,000 BTU air conditioner?

A 10,000 BTU/h AC delivers approximately 2930 W of cooling capacity. Its electrical input draw is typically 900-1200 W depending on efficiency (EER 8-11). Output cooling exceeds electrical input because heat pumps move heat rather than create it.

BTU per hour vs raw BTU — what's the difference?

BTU is energy; BTU/h is the rate of delivering that energy, i.e. power. Confusing the two leads to wrong sizing. HVAC, gas appliances, and grills are always rated in BTU/h, even when the spec sheet just writes 'BTU'.

How many BTU per square foot for AC sizing?

A rough US rule of thumb: 20 BTU/h per square foot of living space, adjusted up for sunny rooms or high ceilings, down for shaded or low-occupancy rooms. A 500 sq ft room needs ~10,000 BTU/h ≈ 2.93 kW.

Is a ton of cooling the same as 12,000 BTU?

Yes — '1 ton of refrigeration' equals 12,000 BTU/h. The unit comes from the historical refrigeration capacity required to freeze one short ton of water in 24 hours. Commercial HVAC routinely uses tons; residential uses BTU/h directly.

Does BTU-to-watts depend on fuel type?

No. BTU and watts are energy and power units, independent of source. A 50,000 BTU/h gas furnace and a 50,000 BTU/h electric heater both deliver the same heat output rate (14.65 kW). Efficiency at producing that output differs by fuel and equipment.

Why do US specs still use BTU?

Inertia and consumer familiarity. The US HVAC and gas appliance industries standardized on BTU/h long before metric adoption was discussed. Migration to watts is slow because installers, sales literature, and consumer expectation are all anchored in BTU.

Related converters

Watts to BTU/h Kilowatts to Watts Joules to Calories