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BTU to Watts Converter

Convert BTU per hour to watts instantly. Enter BTU/hr to get watts by dividing by 3.412142, with the reverse watts to BTU/hr direction shown.

Updated 2026-06-14 · Free · No sign-up · Runs privately in your browser

Show the formula & steps

How the BTU to Watts Converter Works

This tool converts BTU per hour (BTU/hr) to watts (W) and back. Heating and cooling equipment such as air conditioners, furnaces and radiators is rated in BTU/hr, while electrical and scientific power is measured in watts. Both are units of power, so they convert with a fixed factor.

The Formula

Watts = BTU per hour ÷ 3.412142 BTU per hour = watts × 3.412142

The factor comes from the energy in one BTU (1,055.06 joules) spread over an hour (3,600 seconds), giving 0.293071 watts per BTU/hr.

Worked Example

Convert a 12,000 BTU/hr air conditioner (one “ton” of cooling) to watts:

  • Watts = 12,000 ÷ 3.412142 = 3,517 W

A small 5,000 BTU/hr window unit:

  • 5,000 ÷ 3.412142 = 1,465 W

Going the other way, 2,000 W in BTU/hr:

  • BTU/hr = 2,000 × 3.412142 = 6,824 BTU/hr

BTU/hr to Watts Quick Reference

BTU per hourWatts
1,000293
5,0001,465
9,0002,638
12,0003,517
24,0007,034

Output Power vs Electricity Used

A key point: converting BTU/hr to watts gives the heating or cooling output, not how much electricity the appliance consumes. A 12,000 BTU/hr air conditioner produces about 3,517 watts of cooling but may only draw 1,000 to 1,200 watts from the wall, depending on its efficiency rating (EER or SEER). To estimate running cost, look at the unit’s power draw or efficiency, not just its BTU rating.

Frequently asked questions

How many watts is 1 BTU per hour?+

One BTU per hour equals about 0.293071 watts. So 12,000 BTU/hr is about 3,517 watts. To convert BTU/hr to watts, divide by 3.412142.

How do I convert BTU to watts?+

Divide the BTU per hour value by 3.412142. For example, 12,000 BTU/hr ÷ 3.412142 = 3,517 watts. To reverse it, multiply watts by 3.412142 to get BTU/hr.

How many watts is a 12000 BTU air conditioner?+

A 12,000 BTU/hr air conditioner has a cooling output of about 3,517 watts. Note this is the cooling capacity, not the electrical power it draws, which is lower and depends on efficiency.

Is BTU a unit of power or energy?+

A BTU is a unit of energy, but appliance ratings use BTU per hour, which is power. Since watts are also power, this converter treats the BTU figure as BTU per hour for HVAC use.

Does this give the electricity an appliance uses?+

No. BTU/hr converted to watts gives the heating or cooling output, not the electrical consumption. A unit's power draw depends on its efficiency, such as the EER or SEER rating, and is usually lower.