Kwh to BTU Converter
Convert between kilowatt-hours, BTU, therms, and megajoules for energy billing. Enter values for instant results with step-by-step formulas.
Reviewed for accuracy by Manoj Kumar, Mathematics Educator
Kwh to BTU Converter
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Formula: BTU = kWh x 3,412.14
Worked example โ 900 kWh = 3,070,926 BTU = 30.71 therms = 3,240 MJ | Cost: $117.00/month
Formula
BTU = kWh x 3,412.14
One kilowatt-hour equals 3,412.14 BTU. This is derived from 1 watt = 1 joule/second, and 1 BTU = 1,055.06 joules. So 1 kWh = 3,600,000 J / 1,055.06 J/BTU = 3,412.14 BTU. One therm = 100,000 BTU = 29.3 kWh.
Worked Examples
Example 1: Monthly Electricity to BTU
Problem:A household uses 900 kWh of electricity per month at $0.13/kWh. What is the total energy in BTU and therms, and the monthly cost?
Solution:BTU = 900 kWh x 3,412.14 BTU/kWh = 3,070,926 BTU Therms = 3,070,926 / 100,000 = 30.71 therms Megajoules = 900 x 3.6 = 3,240 MJ Monthly cost = 900 x $0.13 = $117.00
Result:900 kWh = 3,070,926 BTU = 30.71 therms = 3,240 MJ | Cost: $117.00/month
Example 2: Gas vs Electric Heating Comparison
Problem:Compare heating costs: natural gas at $1.10/therm (95% furnace) vs electricity at $0.12/kWh (heat pump COP 3.0) for 50 million BTU seasonal heating.
Solution:Gas: 50,000,000 BTU / 100,000 = 500 therms needed At 95% efficiency: 500 / 0.95 = 526.3 therms purchased Gas cost = 526.3 x $1.10 = $578.95 Heat pump: 50,000,000 BTU / 3,412.14 = 14,654 kWh equivalent With COP 3.0: 14,654 / 3.0 = 4,885 kWh purchased Electric cost = 4,885 x $0.12 = $586.17
Result:Gas: $578.95/season vs Heat Pump: $586.17/season (nearly equal in this scenario)
Frequently Asked Questions
How many BTU are in one kilowatt-hour?
One kilowatt-hour (kWh) equals exactly 3,412.14 BTU (British Thermal Units). This conversion factor is derived from the fundamental relationship between electrical energy and thermal energy units. Since 1 watt equals 3.41214 BTU/hr, multiplying by 1,000 watts per kilowatt and 1 hour gives 3,412.14 BTU per kilowatt-hour. This conversion is essential for comparing energy costs between electricity and natural gas, sizing backup heating systems, and calculating the thermal equivalent of electrical energy consumption in residential and commercial buildings.
What is a therm and how does it relate to kWh?
A therm is a unit of heat energy equal to 100,000 BTU, commonly used for natural gas billing in the United States. One therm equals approximately 29.3 kilowatt-hours of energy content. Natural gas utilities typically charge per therm consumed, making the therm-to-kWh conversion essential for comparing heating costs between gas and electric systems. For perspective, one therm of natural gas costs roughly one dollar to two dollars in most US markets, while the equivalent 29.3 kWh of electricity might cost three to five dollars at average residential rates. This price difference explains why natural gas heating is often more economical than electric resistance heating.
How do I compare electricity and natural gas costs?
To compare costs, convert both energy sources to the same unit. Natural gas is typically billed per therm (100,000 BTU) and electricity per kWh (3,412 BTU). Divide your gas cost per therm by 29.3 to get the equivalent cost per kWh of heat content, then compare with your electric rate. However, you must also account for equipment efficiency. A 95 percent efficient gas furnace delivers 95,000 BTU per therm, while an electric heat pump with a COP of 3.0 delivers 10,236 BTU per kWh (3,412 x 3). Factor in both the energy cost per BTU delivered and equipment maintenance costs for a complete comparison.
What is the difference between kWh and kW?
Kilowatts (kW) measure power, which is the rate of energy use at any given moment, while kilowatt-hours (kWh) measure energy, which is the total amount of power consumed over time. Think of it like a car: kW is the speedometer reading (how fast), and kWh is the odometer reading (how far). A 1,500-watt (1.5 kW) space heater running for 2 hours uses 3 kWh of energy. Your electric bill charges for kWh consumed, not kW. Understanding this distinction is critical for estimating energy costs, sizing electrical systems, and comparing energy consumption across different appliances and time periods.
How many BTU does a typical home use per year?
A typical US home uses approximately 80 to 100 million BTU per year across all energy sources including electricity, natural gas, heating oil, and propane. This equals roughly 23,000 to 29,000 kWh equivalent. Space heating accounts for the largest share at about 42 percent (34 to 42 million BTU), followed by water heating at 18 percent, air conditioning at 6 percent, and appliances and lighting at the remainder. Climate, home size, insulation quality, and equipment efficiency all significantly affect actual usage. Homes in cold northern climates may use 120 to 150 million BTU annually, while those in mild climates may use only 40 to 60 million BTU.
How do I calculate my monthly energy cost from BTU usage?
To calculate monthly costs from BTU, first determine the energy source. For electricity, divide total BTU by 3,412.14 to get kWh, then multiply by your rate per kWh. For natural gas, divide total BTU by 100,000 to get therms, then multiply by your cost per therm. For example, if your furnace uses 5 million BTU per month of natural gas at a cost of 1.20 dollars per therm, the calculation is 5,000,000 divided by 100,000 equals 50 therms, times 1.20 dollars equals 60 dollars per month. Always include demand charges, delivery charges, and taxes that appear on your utility bill for an accurate total cost estimate.
How does a heat pump change the BTU-to-kWh cost calculation?
Heat pumps dramatically change the energy cost calculation because they move heat rather than generating it, achieving efficiencies of 200 to 400 percent. A heat pump with a coefficient of performance (COP) of 3.0 delivers 3 units of heat energy for every 1 unit of electrical energy consumed, meaning 1 kWh of electricity produces approximately 10,236 BTU of heating (3,412 x 3). This makes electric heat pump heating competitive with or cheaper than natural gas in many markets, even though electricity costs more per BTU than gas. In moderate climates where COP values remain high year-round, heat pumps can reduce heating costs by 40 to 60 percent compared to gas furnaces.
What is the energy content of different fuels in BTU?
Different fuels contain varying amounts of energy per unit. Natural gas contains approximately 1,030 BTU per cubic foot or 100,000 BTU per therm. Propane contains about 91,500 BTU per gallon. Heating oil (No. 2 fuel oil) contains approximately 138,500 BTU per gallon. Gasoline contains about 120,000 BTU per gallon. Wood pellets contain roughly 16.5 million BTU per ton. Coal ranges from 17 to 30 million BTU per ton depending on grade. Electricity provides exactly 3,412 BTU per kWh at the point of use but requires about 10,000 BTU of primary energy per kWh at the power plant due to generation and transmission losses.
How do energy efficiency ratings use BTU and kWh together?
Energy efficiency ratings frequently combine BTU and kWh measurements. The EER (Energy Efficiency Ratio) of an air conditioner is calculated as cooling capacity in BTU/hr divided by power input in watts. The SEER (Seasonal Energy Efficiency Ratio) divides seasonal BTU output by seasonal watt-hour input. The AFUE (Annual Fuel Utilization Efficiency) for furnaces expresses the percentage of fuel BTU actually converted to useful heat. The HSPF (Heating Seasonal Performance Factor) for heat pumps divides BTU of heat delivered by watt-hours consumed. Higher values indicate better efficiency in all these ratings, and understanding the BTU-to-kWh relationship is essential for interpreting and comparing them.
References
Reviewed for accuracy by Manoj Kumar, Mathematics Educator ยท Editorial policy
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