Then why do HVAC specs say "12,000 BTU"?

Because the industry abbreviates BTU per hour to BTU. An air conditioner labelled 12,000 BTU produces 12,000 BTU every hour, so its power output is 12,000 ÷ 3,412.1416 = 3.5169 kW — the classic "one ton" of cooling. Keeping the duration at 1 hour on this page gives exactly that figure.

What is 24,000 BTU in kW?

Over one hour, 24,000 BTU = 7.0337 kW of heating or cooling output — typical for a large living room or an open-plan floor. Over 24 hours the same energy averages 0.2931 kW.

Does the kW figure mean electricity consumed?

No. For a heat pump or air conditioner the BTU/h rating is heat output. Electrical input is output divided by COP (heating) or EER/SEER (cooling), which is typically three to four times smaller.

How do I convert BTU to kWh instead?

Divide by 3,412.1416 and stop there — no duration needed, because BTU and kWh are both energy units. 100,000 BTU (one US therm) = 29.3071 kWh.

Where does 3,412.1416 come from?

From the International Table BTU (1,055.05585262 J, NIST SP 811) and the SI definition of the watt as one joule per second: 3,600,000 J ÷ 1,055.05585262 J = 3,412.1416 BTU per kWh. The factor is derived, not approximate.

BTU to Kilowatts Converter

One BTU equals 0.00029307107 kilowatts at 1 h (1 BTU = 0.00029307107 kW).

BTU (BTU)

Kilowatts (kW)

Duration (h) — required

Required, because BTU is energy and kW is power. Ask yourself which figure you have: an equipment capacity stamped "12,000 BTU" is really 12,000 BTU per hour, so leave the duration at 1 hour. A fuel or gas quantity in BTU consumed over a period needs that period entered here to give the average power.

1 BTU=0.00029307107 kW

kW = BTU ÷ 3,412.1416 ÷ 1 h

What does this result mean?

2.93e-4 kWh of energy. Here is what that quantity actually does.

Average household electricity: 2.79e-5 days
EV battery charge: 3.81e-4% of a 77 kWh pack
EV driving range: 1.63e-3 km
Cost at typical tariff: €0.00
CO₂ from grid electricity: 1.03e-4 kg CO₂e
Kettle boils: 2.66e-3

Equivalences use documented averages and are intended for scale and decision support, not billing. Your tariff, grid mix and vehicle efficiency will differ — see the methodology page for every constant used. See the constants and sources behind these figures.

Quick Answer: BTU to Kilowatts

One BTU equals 0.00029307107 kilowatts at 1 h (1 BTU = 0.00029307107 kW).

Conversely, 1 kW = 3,412.14163 BTU at 1 h.

Formula: kW = BTU ÷ 3,412.1416 ÷ 1 h

Worked examples

3412 BTU = 0.999958491 kW at 1 h
5000 BTU = 1.46535535 kW at 1 h
6000 BTU = 1.75842642 kW at 1 h

Method and limitations

BTU measures energy; kilowatts measure power. The two are only comparable across a stated time interval, so this calculator requires a duration. Convert the BTU figure to kWh (÷ 3,412.1416), then divide by the number of hours over which that energy is delivered to get the average power in kW. Leaving the duration at 1 hour reproduces the standard HVAC conversion, because an appliance rated in BTU/h delivers that many BTU in one hour. Calculations use full-precision constants; displayed values are rounded to at most 9 significant figures. This is not a fixed unit pair. The result depends on duration, so always state the duration (1 h here) alongside the answer.

Each factor is exact by definition, derived from exact definitions, or a documented conventional value — see the methodology and sources.

Conversion Formula

kW = BTU ÷ 3,412.1416 ÷ 1 h

This formula uses the duration currently set in the calculator (1 h). Change it above and this formula updates with it — the relationship is not a fixed unit pair.

Complete Guide to BTU to Kilowatts Conversion

What is a BTU?

The British thermal unit (BTU) is a quantity of energy: the heat needed to raise one pound of water by one degree Fahrenheit, standardised as the International Table BTU of 1,055.05585262 joules. It is the imperial counterpart of the joule, not of the watt.

What is a Kilowatts?

The kilowatt (kW) is the SI unit of power — one thousand joules per second. It describes a rate, so it can only be derived from an energy figure once the time over which that energy flows is known.

How the Conversion Works

First convert the energy: BTU ÷ 3,412.1416 = kWh. Then divide by the duration in hours to get average power in kW. If the figure you started with was really a BTU per hour rating, the duration is one hour by construction and the second step collapses to nothing — which is why the familiar ÷ 3,412.14 shortcut works for equipment capacities and only for equipment capacities.

Why This Conversion Matters

Sizing heating and cooling equipment means matching a capacity in kW to a building heat loss in kW, while US equipment is labelled in BTU/h. Treating an energy figure as if it were a capacity, or vice versa, produces an error equal to the number of hours involved — a factor of 24 on a daily gas figure. Naming the duration removes that whole class of mistake.

Scientific Context

The dimensional distinction is the same one that separates kWh from kW on an electricity bill: energy is power integrated over time. NIST SP 811 lists the BTU under energy, and the BIPM SI Brochure defines the watt as J/s, so no single number can convert between them.

Step-by-Step Conversion Guide

Follow these steps to convert btu to kilowatts manually:

Start with your value in btu

Example: You want to convert 6000 BTU

Apply the conversion formula

Use the formula: kW = BTU ÷ 3,412.1416 ÷ 1 h

Calculate the result

6000 BTU = 1.7584 kW

✓

Verify your answer

Use our calculator above to double-check your manual calculation.

Quick Mental Math Tip

Common Conversions

Calculated at 1 h (duration). Change the value in the calculator above and this table recalculates.

BTU to Kilowatts conversion table at 1 h
BTU (BTU)	Kilowatts (kW)	Kilowatts → BTU
3412 BTU	0.999958	3412 kW = 11,642,200 BTU
5000 BTU	1.46536	5000 kW = 17,060,700 BTU
6000 BTU	1.75843	6000 kW = 20,472,800 BTU
9000 BTU	2.63764	9000 kW = 30,709,300 BTU
12000 BTU	3.51685	12000 kW = 40,945,700 BTU
18000 BTU	5.27528	18000 kW = 61,418,500 BTU
24000 BTU	7.03371	24000 kW = 81,891,400 BTU
30000 BTU	8.79213	30000 kW = 102,364,000 BTU
36000 BTU	10.5506	36000 kW = 122,837,000 BTU
48000 BTU	14.0674	48000 kW = 163,783,000 BTU
60000 BTU	17.5843	60000 kW = 204,728,000 BTU
100000 BTU	29.3071	100000 kW = 341,214,000 BTU

Frequently Asked Questions

Not without a time interval. BTU is energy and kW is power, so the question "how many kW is 12,000 BTU?" is incomplete in the same way "how many km/h is 100 km?" is incomplete. State the duration and the answer becomes well defined: 12,000 BTU delivered over one hour is 3.5169 kW; the same 12,000 BTU spread over eight hours is 0.4396 kW.

Related Guides & Articles

View all

🎓

Metric vs Imperial: The Complete Guide to Measurement Systems

The world is divided between two major measurement systems: metric and imperial. Understanding the d...

🎓

The Fascinating History of Temperature Scales

Temperature is something we experience every day, yet the scales we use to measure it have fascinati...

🎓

The International System of Units (SI): The Language of Science

The International System of Units (SI) is the modern metric system and the world most widely used sy...

🎓

The Complete Guide to Unit Conversion: From Basics to Mastery

Unit conversion is the essential skill that bridges the gap between different measurement systems. W...

Want to learn more about energy conversions?

Browse all energy articles →

People Also Convert

Related calculators users frequently visit alongside btu to kilowatts.

Conversion factors on this page are either exact by definition, derived from exact definitions, or conventional values in documented use. Each is listed with its source in our conversion methodology and sources, which cites the BIPM SI Brochure, NIST Special Publication 811 and the relevant IEC or national standards. Results are rounded for display only; calculations use full precision.