BTU to kWh: A Complete Energy Conversion Guide 2025
Understanding how to convert BTUs (British Thermal Units) to kilowatt-hours (kWh) is an essential skill for anyone working with heating, cooling, or energy consumption. Whether you're managing an HVAC system, reviewing your energy bill, or comparing appliance efficiency, converting BTUs to kWh enables more accurate energy planning and cost estimation.
In this comprehensive guide, we'll explain the definitions of BTUs and kWh, walk through the conversion formula with practical examples, cover common mistakes to avoid, and provide a ready-to-use conversion table. Let’s get started now!
What Are BTUs and Kilowatt-Hours?
BTUs and kilowatt-hours both measure energy, but they originate from different systems and are used in different contexts.
A BTU, or British Thermal Unit, is a traditional unit of heat energy. It is defined as the amount of energy required to raise the temperature of one pound of water by one degree Fahrenheit. BTUs are widely used in the United States, especially for rating heating and cooling equipment such as air conditioners, furnaces, and water heaters.
A kilowatt-hour (kWh), on the other hand, is a metric unit of energy most commonly used for electrical energy. One kilowatt-hour represents the energy used by a device drawing one kilowatt of power over the course of one hour. It's the standard billing unit for electricity consumption on utility bills.
Although BTUs and kWh measure the same physical quantity—energy—they do so in different units. This is why a reliable method for converting between them is necessary for comparing equipment or calculating energy use.
How to Convert BTU to kWh
Now that you know what BTU and kWh mean, let’s walk through how to convert British thermal units to kilowatt hours.
The Basic Conversion Formula
To convert BTU to kWh, use the following formula:
1 kWh = 3,412 BTU
or
1 BTU = 0.000293 kWh
So, the formula is:
BTU × 0.000293 = kWh
Example Conversion
To better understand how this conversion is applied in real-life situations, let’s see some examples below.
Example 1: BTU to kWh
Let’s say you have a portable air conditioner rated at 12,000 BTU. To find out how much energy it uses in kWh:
12,000 BTU × 0.000293 = 3.516 kWh
This means the unit will use approximately 3.52 kWh if it runs continuously for one hour.
Example 2: kWh to BTU
While converting BTUs to kilowatt-hours is common, it’s equally useful to go the other way, converting kWh to BTUs, especially when you're reviewing electricity usage or comparing it to thermal output.
For example, the EcoFlow DELTA Pro Portable Power Station has a base capacity of 3.6 kWh, expandable up to 25 kWh with extra batteries. If you want to understand how much thermal energy this storage can provide (in BTUs), use the conversion:
1 kWh = 3,412 BTU
Conversion Formula:
kWh × 3,412 = BTUs
When you use only the base capacity of 3.6 kWh:
3.6 kWh × 3,412 = 12,283.2 BTU
That means the base unit can deliver 12,283 BTUs of energy, roughly equivalent to running a 12,000 BTU air conditioner for about one hour.
When you add extra batteries to use the 25 kWh max capacity:
25 kWh × 3,412 = 85,300 BTU
At full expansion, the EcoFlow DELTA Pro can provide 85,300 BTUs of energy, enough to power high-demand devices like heaters, AC units, or electric stoves for extended periods, making it a reliable home backup for heavy-duty or long-duration off-grid power.
From these examples, we know that converting BTU to kWh is essential, particularly for estimating the energy consumption of heating and cooling systems. Understanding and noting this conversion between BTU and kWh helps you in:
Estimating energy costs: If your electricity rate is $0.13/kWh, then running a 12,000 BTU unit for an hour costs: 12,000 BTU × 0.000293 kWh × $0.13 = $0.46/hour.
Comparing appliances: You can compare energy usage between BTU-rated and kWh-rated systems to know which is more energy-efficient.
Sizing solar or battery systems: Helps plan the best capacity of a portable power station if you rely on off-grid energy sources.
EcoFlow DELTA Pro Portable Power Station
Common Mistakes to Avoid in BTU to kWh Conversion
BTU to kWh conversion is essential when comparing energy use and costs, especially for heating and cooling systems. However, several common mistakes can lead to inaccurate calculations and poor energy decisions. Here are the most frequent errors to watch out for and how to avoid them:
Use the Wrong Conversion Factor
The most basic mistake is using an incorrect conversion rate. The standard conversion is:
1 kWh = 3,412 BTU
or
1 BTU = 0.000293 kWh
Some users mistakenly round the factor too aggressively (e.g., using 3,400 instead of 3,412), which can cause noticeable discrepancies in large calculations.
Tip: Always use accurate values for conversions, especially in energy audits or cost projections.
Confuse Power with Energy
BTU and kWh measure energy, not power. People often confuse BTU/h (BTUs per hour, a measure of power) with total BTUs.
For example, a heater rated at 10,000 BTU/h doesn’t mean it uses 10,000 BTU total—it means it uses 10,000 BTUs every hour it runs.
Tip: Always confirm whether the BTU value refers to rate (BTU/h) or total energy (BTU) before converting.
Not Accounting for Usage Time
Another mistake is converting BTU to kWh without considering how long the device operates. Energy (kWh) equals power (kW) × time (hours). So, converting BTU to kWh only gives you accurate results when factoring in how long the energy is being consumed.
Tip: To estimate energy cost or consumption, always multiply power by time.
Ignore Efficiency Ratings
Appliances like furnaces and air conditioners have efficiency ratings (e.g., SEER, AFUE). Ignoring these can lead to misjudging actual energy use.
Tip: For accurate conversions, apply the efficiency factor to calculate real energy consumption or output in kWh or BTU.
Overlook Unit Consistency
Mixing up units, such as inputting kilojoules or megajoules instead of BTUs, can throw off your entire calculation.
Tip: Double-check that all units are compatible before performing conversions.
BTU to kWh Conversion Table
Although the conversion formula is given above, making calculations repeatedly isn’t always convenient. Use this quick reference table to instantly find the kWh equivalent of common BTU values—no math required.
BTUs | Kilowatt-Hours (kWh) |
1 | 0.000293 |
100 | 0.029307 |
200 | 0.058614 |
300 | 0.087921 |
400 | 0.117228 |
500 | 0.146536 |
1,000 | 0.293071 |
5,000 | 1.465355 |
10,000 | 2.930711 |
20,000 | 5.861421 |
30,000 | 8.792132 |
40,000 | 11.722843 |
50,000 | 14.653554 |
75,000 | 21.980330 |
100,000 | 29.307107 |
Conclusion
Converting from BTU to kWh is a vital skill in today's energy-conscious world. While BTUs are most commonly used in heating and cooling contexts, kilowatt-hours dominate electricity billing and energy planning. Being able to convert between them enables you to compare systems more accurately, budget for energy costs, and optimize your power usage.
By learning how to apply the correct formula, avoiding common mistakes, and using quick-reference tables, you can confidently translate energy values across different units. So whether you're managing a home upgrade, analyzing utility data, or planning an off-grid power station, this knowledge puts you in control!
FAQs
How many BTU is 1 kWh of electricity?
One kilowatt-hour (kWh) of electricity is equal to approximately 3,412.14 BTU. This means that if a device consumes 1 kWh of energy, it delivers the equivalent of 3,412.14 British Thermal Units. This conversion is useful for comparing electrical energy usage to heating or cooling output rated in BTUs.
How do I convert BTU to kW?
To convert BTU to kilowatts (kW), use the formula: BTU ÷ 3,412 = kWh, then divide by the number of hours to get kW. For a direct power conversion: 1 BTU/h = 0.000293 kW. So, multiply BTU per hour by 0.000293 to get kW. Always ensure you're using BTU/h for power conversions.
How many kW is 12,000 BTU/h?
To convert 12,000 BTU/h to kilowatts (kW), multiply by the conversion factor: 1 BTU/h = 0.000293 kW. So, 12,000 × 0.000293 = 3.516 kW. This means a 12,000 BTU/h air conditioner has a cooling power of approximately 3.52 kW.
How many kW is 10,000 BTU/h?
To convert 10,000 BTU/h to kilowatts (kW), multiply by the conversion factor: 1 BTU/h = 0.000293 kW. So, 10,000 × 0.000293 = 2.93 kW, indicating a 10,000 BTU/h appliance has a power output of approximately 2.93 kW.