kW To BTU Converter Calculator: How Many BTU in a kW

This page features a couple calculators and Tables showing to quickly assist you in converting kilowatts to BTU.

Why would you want to convert kW to BTU per hour, or kW = BTU/hour?

Cooling and heating capacity are often listed by kW, so to determine how powerful the unit is, converting kW to BTU is necessary.

If you know how much energy your air conditioner is using, you can determine how much heat it is removing from your home each hour of use. In other words, the amount of cooling it provides.


These are units of power – electricity. One kW = 1,000 watts. Your energy company meters the amount of electricity you use in kW.

1 kW = 3412 BTU/hour rounded off just a bit from the actual number of 3412.14164.


These are British Thermal Units, a measurement of energy, also explained as a unit of heat. If you like technical answers, then 1 BTU is the amount of power required to raise the temperature of one pound of water by 1° F.

BTU per hour is a rate of energy transfer.

Calculator 1: Direct Equivalent kW to BTU

This calculator allows you to quickly find the BTU per kWh, which starts by showing 1 kw to BTU is 1 kW = 3,412 BTU/hour

This is a very simple, one-step kW to BTU calculator. If you know the kW rating for your AC or other appliance, simply input the number. And the calculator will crunch the result and give you the number of BTU/hour used.

Input kW – That’s all you have to do to have the calculator give you the answer in BTU/hour.

This handy Direct Equivalent kW to BTU shows the math already done. So, you might ask, how many BTU is one kW? Or What is 3 kW in BTU? 5 kW in BTU? And so forth.

kw to btu conversion table

KilowattsBtu Per Hour
1 kW3,412 BTU/h
2 kW6,824 BTU/h
2.5 kW8,530 BTU/h
3 kW10,236 BTU/h
3.5 kW11,942 BTU/h
4 kW13,648 BTU/h
5 kW17,060 BTU/h
9 kW30,708 BTU/h
10 kW34,120 BTU/h
12 kW40,944 BTU/h
15 kW51,180 BTU/h
16 kW54,592 BTU/h
20 kW68,240 BTU/h
30 kW102,360 BTU/h


Question: What is 1 kW to BTU? 

Answer: 1 kW to BTU = 3,412 BTU/hour

Question: Convert 5 kW to BTU? 

Answer: 5 kW to BTU = 17,060 BTU/hour

Today’s central air conditioners range in BTU from 18,000 to 60,000 BTU. Using our handy chart, you can see this range of a little more than 6 kW to about 18 kW.

Window air conditioners typically range from about 6,000 BTU to 24,000 BTU, so roughly 2 kW to 7 kW using the direct equivalent.

Here are common room air conditioner sizes and their kW equivalence. Numbers are approximate, but very close to precise.

  • 5,000 BTU = 1.5 kW
  • 6,000 BTU = 1.8 kW
  • 8,000 BTU = 2.4 kW
  • 10,000 BTU = 3 kW
  • 12,000 BTU = 3.5 kW
  • 18,000 BTU = 5.4 kW

Calculator 2: Air Conditioner kW to BTU

Factoring Energy Efficiency Rating

EER is the energy efficiency rating, a measurement of how efficiently an air conditioner converts electricity to cooling power.

In the last few years, most manufacturers of air conditioners have begun listing the EER in the product information, sometimes along with other ratings like SEER and Combined EER or CEER.

Step 1: Input the kW measurement.

Step 2: Add the EER Rating

You can type in the number or use the arrows to raise or lower the default number shown.

The EER of your air conditioner should be listed in the unit itself along with the model and serial number. You might also find it online by searching the AC model number.

The more efficient an air conditioner is, the more BTU it can produce with the same amount of energy. Or to put it another way, it uses less energy to produce the desired cooling.

For example, 4 kW times 12 EER yields 48,000 BTU/hour.

But if another unit uses 4 kW but has an EER of 9, it will dissipate only 36,000 BTU/hour of heat.

Again, we’ve produced a quick-glance chart with calculations already made for common kW sizes and BTU/h ratings:

KilowattsBtu Per Hour
1 kW12,000 BTU/h (1 Ton)
1.5 kW18,000 BTU/h (1.5 Ton)
2 kW24,000 BTU/h (2 Ton)
2.5 kW30,000 BTU/h (2.5 Ton)
3 kW36,000 BTU/h (3 Ton)
3.5 kW42,000 BTU/h (3.5 Ton)
4 kW48,000 BTU/h (4 Ton)
5 kW60,000 BTU/h (5 Ton)
* Based on EER Rating: 12

What Else Do You Want to Know?

Pick HVAC has a growing toolbox of handy calculators covering a wide range of uses.

Do you want to Convert BTU to kW?

How many BTU AC is right for you?

Convert SEER to EER?

Those are just a few of the many calculators we’ve created to make life a little easier for you as you consider your home’s heat needs, cooling demands, costs and more.

Written by

Rene has worked 10 years in the HVAC field and now is the Senior Comfort Specialist for PICKHVAC. He holds an HVAC associate degree and EPA & R-410A Certifications.

Leave a Comment Protection Status