BTU/hr = kW × 3,412.142
To go back the other way, divide BTU/hr by 3,412.142.
A 10 kW cooling load is about 34,121 BTU/hr. The constant comes from the definition of the BTU and the number of seconds in an hour — nothing more exotic than that.
kW to BTU/hr
Convert a heating or cooling load in kilowatts into BTU per hour, the unit on most HVAC equipment.
For the electrical side of the same plant, use the main kVA to kW converter.
kW to BTU/hr Calculator
BTU/hr = kW × 3,412.14210 kW
kW
Quick values
At a glance
BTU/hr = kW × 3,412.142
- Heat rate
- 34,121 BTU/hr
- Thermal power
- 10 kW
Every diagram and table on this page updates with the calculator above.
Output
Live34,121BTU/hr
BTU/hr = 10 kW × 3,412.142 = 34,121.4 BTU/hr
Per minute569 BTU/min
Refrigeration2.84 tons
The kW to BTU/hr Formula
The conversion
LiveInput10kW
Result34,121.4BTU/hr
What a BTU Actually Is
- BTU
- British thermal unit — the heat needed to raise one pound of water by one degree Fahrenheit. About 1,055 joules.
- BTU/hr
- A rate of heat flow, which makes it directly comparable with kilowatts. This is what equipment is rated in.
- Ton of refrigeration
- 12,000 BTU/hr, from the cooling produced by melting one short ton of ice over 24 hours.
A "12,000 BTU" air conditioner is not 12,000 BTU
The industry drops the "per hour" in marketing. The unit is a rate: 12,000 BTU/hr, which is 3.5 kW and exactly one ton of cooling.
Two rates, one load
LiveHVAC Capacity Conversion Chart
Common air conditioning and heat pump capacities in all three units.
Capacity chart
Live| kW | Heat rate (BTU/hr) | Refrigeration (tons) |
|---|---|---|
| 1 kW | 3,412 | 0.28 |
| 2 kW | 6,824 | 0.57 |
| 2.5 kW | 8,530 | 0.71 |
| 3.5 kW | 11,942 | 1 |
| 5 kW | 17,061 | 1.42 |
| 7 kW | 23,885 | 1.99 |
| 10 kW | 34,121 | 2.84 |
| 14 kW | 47,770 | 3.98 |
| 17.5 kW | 59,712 | 4.98 |
| 25 kW | 85,304 | 7.11 |
| 35 kW | 119,425 | 9.95 |
| 50 kW | 170,607 | 14.22 |
| 100 kW | 341,214 | 28.43 |
| 200 kW | 682,428 | 56.87 |
Decoding an HVAC Nameplate
Cooling capacity
The heat the unit removes, in BTU/hr or kW. Quoted at standard test conditions, not at your design day.
Power input
The electricity consumed, always much smaller than the cooling capacity. Never confuse the two.
EER / SEER / COP
Efficiency ratios. Cooling output divided by electrical input, in mixed or consistent units.
A "12,000 BTU" split unit
Given
- Cooling: 12,000 BTU/hr
- Power input: 1,100 W
- EER: 10.9
Working
- Cooling in kW = 12,000 ÷ 3,412 = 3.52 kW
- COP = 3,520 ÷ 1,100 = 3.2
A 3.5 kW cooling unit drawing 1.1 kW of electricity — one ton of refrigeration at a COP of 3.2.
Equipment classes
LiveRoom unit
Light commercial
Packaged unit
Chiller
2.84 tons
Getting to the Right Capacity
Floor area rules of thumb are a starting point and nothing more. A proper heat load calculation adds up every source of heat entering the space.
- Fabric gains
Conduction through walls, roof and glazing, driven by the design temperature difference.
- Solar gains
Direct and diffuse radiation through glazing — often the largest single component on a south-facing façade.
- Internal gains
People at roughly 100 W each, lighting, computers and any process equipment.
- Ventilation and infiltration
Outside air brought in deliberately or leaking in, at its own temperature and humidity.
- Apply diversity
Peak solar and peak occupancy rarely coincide. Adding every worst case gives an oversized, short-cycling system.
Oversizing is not the safe option
An oversized unit short-cycles, dehumidifies poorly and wears out faster. Comfort usually gets worse, not better.
Capacity gauge
Live2.84 tonsTons of refrigeration
Three Units for the Same Machine
| Market | Preferred unit | 3.5 kW unit is quoted as |
|---|---|---|
| United States | BTU/hr and tons | 12,000 BTU/hr or 1 ton |
| Europe | kW | 3.5 kW |
| Middle East | tons | 1 ton |
| Asia-Pacific | kW or BTU/hr | 3.5 kW or 12,000 BTU/hr |
When comparing quotes across markets, convert everything into one unit first. A specification that mixes them invites a factor-of-three error at tender stage.
Three capacities
Live3.5 kW
- BTU/hr
- 11,942
- Tons
- 1 TR
10 kW
- BTU/hr
- 34,121
- Tons
- 2.84 TR
35 kW
- BTU/hr
- 119,425
- Tons
- 9.95 TR
Every Power Converter in One Place
29 calculators built on the same maths as the tool above. Each one has its own inputs, interactive diagrams and worked examples.
kW to kVA
kVA = kW ÷ PFkVA to MW
MW = kVA × PF ÷ 1,000kVA to MVA
MVA = kVA ÷ 1,000VA to kVA
kVA = VA ÷ 1,000VA to kW
kW = VA × PF ÷ 1,000kVA to Watts
W = kVA × 1,000 × PFkW to Watts
W = kW × 1,000kW to GW
GW = kW ÷ 1,000,000kVA to kW (Single Phase)
kW = kVA × PFkVA to Amps
A = kVA × 1,000 ÷ (V × √3 for 3-phase)kVA to Amps (Three Phase)
A = kVA × 1,000 ÷ (√3 × V)Amps to kW
kW = √3 × V × A × PF ÷ 1,000kW to Volts
V = kW × 1,000 ÷ (√3 × A × PF)kW to kWh
kWh = kW × hourskW to MWh
MWh = kW × hours ÷ 1,000kW to GJ
GJ = kW × hours × 0.0036kW to kJ
kJ = kW × secondskW to Joules
J = kW × 1,000 × secondskW to HP
hp = kW × 1.34102kW to BHP
bhp = kW × 1.34102kW to Nm
N·m = 9549.3 × kW ÷ rpmkW to Torque
T = 9549.3 × kW ÷ rpmkW to RPM
rpm = 9549.3 × kW ÷ N·mkW to CC
cc = (kW ÷ kW per litre) × 1,000Current
kW to BTU/hr
BTU/hr = kW × 3,412.142kW to Ton
TR = kW ÷ 3.51685kW to GPM
GPM = BTU/hr ÷ (500 × ΔT)kW to CFM
CFM = BTU/hr ÷ (1.08 × ΔT)kW to PSI
bar = kW × η × 600 ÷ L/minkW to BTU/hr Questions
Common questions about converting kw to btu/hr.
1 kW is 3,412.14 BTU per hour.
About 3.52 kW, which is also one ton of refrigeration.
Multiply kilowatts by 3,412.142. To go the other way, divide BTU/hr by 3,412.142.
A BTU is energy. BTU per hour is power, which is what makes it comparable with kilowatts.
It depends on heat gains, not floor area alone. As a very rough guide, allow 0.1–0.15 kW per square metre for an office, then confirm with a load calculation.
No. That is the cooling output. Electrical input is the cooling capacity divided by the COP — typically three to four times smaller.