Ton to kW Converter

Convert tons of refrigeration (TR) to kilowatts and back — plus BTU/hr, kcal/h, watts, and horsepower — using the exact definition 1 TR = 3.5168525 kW = 12,000 BTU/hr. Includes an AC room-sizing helper and an EER/COP electricity estimator.

TR ⇄ kW converter

Type a value, pick the units, convert both directions instantly.

Value

From

Result

3.5168525 kW

1 TR × 3.5168525 = 3.5168525 kW

Unit	Value

Common AC sizes: tons to kW table

Typical residential and light-commercial air conditioner ratings, converted exactly.

Tonnage (TR)	kW	BTU/hr	Common name
0.5 TR	1.75842625	6,000	½ ton
0.75 TR	2.637639375	9,000	≈ 1 PK (Indonesia)
1 TR	3.5168525	12,000	1 ton
1.5 TR	5.27527875	18,000	1½ ton
2 TR	7.033705	24,000	2 ton
2.5 TR	8.79213125	30,000	2½ ton
3 TR	10.5505575	36,000	3 ton
5 TR	17.5842625	60,000	5 ton

AC room-sizing helper

Rough rule of thumb for tropical climates: multiply room area by a cooling-load factor.

Room area (m²)

Load factor (BTU/hr per m²)

Estimated cooling load

12,000 BTU/hr ≈ 1 TR

Disclaimer: this is a rule of thumb (±20–25% uncertainty), not a substitute for a proper heat-load calculation. Windows, occupants, and equipment all change the real load — when in doubt, have an HVAC technician verify.

EER / COP electricity estimator

Tonnage tells you cooling capacity — EER/COP tells you what it costs to run. Enter your unit's rating to estimate electrical input.

Cooling capacity (TR)

Rating type

Rating value

Hours per day (optional)

Estimated electrical input (full load)

1.005 kW

Formula: electrical kW = cooling kW ÷ COP, with COP = EER ÷ 3.41214. Real consumption is lower when the thermostat cycles or the unit runs at part load.

How the number 3.5168525 is derived

One ton of refrigeration comes from the heat needed to melt 1 short ton (2,000 lb) of ice at 0 °C in 24 hours. Ice needs 144 BTU per pound to melt:

2,000 lb × 144 BTU/lb ÷ 24 h = 12,000 BTU/hr

Convert to SI: 12,000 BTU/hr × 0.29307107 W/(BTU/hr) = 3,516.85 W = 3.5168525 kW (NIST SP 811 lists 3,516.853 W). That is the modern exact definition — every converter on this page pivots through it, so TR ⇄ kW ⇄ BTU/hr ⇄ kcal/h ⇄ HP all agree with each other.

Scope boundary: three different “tons”

The word “ton” means three unrelated things. This tool converts only the first one.

1. Ton of refrigeration (TR)

Unit of power — a cooling rate. 1 TR = 3.5168525 kW = 12,000 BTU/hr. This page's converter.

2. Metric ton (tonne)

Unit of mass. 1 t = 1,000 kg. For that, use a weight converter.

3. US short ton

Unit of mass. 1 short ton = 2,000 lb = 907.185 kg. Also a weight-converter job.

Nearby units you may meet

Cooling tower ton = 15,000 BTU/hr — bigger than a refrigeration ton; it includes heat from pumps and auxiliaries.
Japanese refrigeration ton ≈ 3.86 kW (≈ 3,320 kcal/h) — about 10% larger than the US ton; common in Japanese/Korean textbooks.
PK (paardekracht) — Indonesian/Dutch AC sizing: 1 PK ≈ 9,000 BTU/hr ≈ 0.75 TR, not 1 ton.

Frequently asked questions

How many kW is 1 ton of refrigeration?

Exactly 3.5168525 kW. By modern definition, 1 ton of refrigeration (TR) equals 12,000 BTU/hr, and 12,000 BTU/hr converts to 3.5168525 kW. Most tables round it to 3.517 kW or 3.52 kW, which is the same value rounded.

What is the formula to convert tons of refrigeration to kW?

Multiply by 3.5168525: kW = TR x 3.5168525. For example, 5 TR x 3.5168525 = 17.5842625 kW. To go the other way, divide: TR = kW / 3.5168525, so 10 kW / 3.5168525 = 2.8435 TR.

How many kW is a 1.5 ton AC? A 2 ton AC?

A 1.5 ton AC = 1.5 x 3.5168525 = 5.2753 kW of cooling capacity (18,000 BTU/hr). A 2 ton AC = 7.0337 kW (24,000 BTU/hr). A 1 ton AC = 3.5169 kW (12,000 BTU/hr), and a 5 ton unit = 17.5843 kW (60,000 BTU/hr). These are cooling capacities, not the electricity the unit consumes.

Does the “ton” in AC tonnage refer to weight?

No. A ton of refrigeration is a unit of power (cooling rate), not mass. It comes from the heat needed to melt 1 short ton (2,000 lb) of ice at 0°C in 24 hours: 2,000 lb x 144 BTU/lb / 24 h = 12,000 BTU/hr. Your AC does not weigh one ton because it is rated “1 ton”.

What is the difference between a ton of refrigeration, a metric ton, and a US ton?

They are three unrelated units sharing one word. A ton of refrigeration is a unit of power: 3.5168525 kW of cooling. A metric ton (tonne) is a unit of mass: 1,000 kg. A US short ton is also mass: 2,000 lb (907.185 kg). This converter only handles the refrigeration ton; use a weight converter for mass tons.

How do I convert kW to tons of refrigeration?

Divide kW by 3.5168525. Example: 7 kW / 3.5168525 = 1.9904 TR. You can also go through BTU/hr: multiply kW by 3,412.14 to get BTU/hr, then divide by 12,000 to get tons of refrigeration.

How many BTU/hr are in 1 kW?

3,412.14 BTU/hr per kW (exactly 12,000 / 3.5168525). So a 3.5168525 kW cooling load equals 12,000 BTU/hr, which is exactly 1 ton of refrigeration. The reverse factor: 1 BTU/hr = 0.00029307 kW.

How many kcal/h is 1 ton of refrigeration?

3,023.95 kcal/h, using the IT calorie convention (1 kcal/h = 1.163 W) standard in HVAC engineering. Some tables show 3,025.97 kcal/h instead — that uses the thermochemical calorie (4,184 J). Both describe the same cooling rate; the 0.07% difference is just the calorie definition.

What are EER and COP, and how are they related?

EER (Energy Efficiency Ratio, US) = cooling output in BTU/hr divided by electrical input in watts. COP (Coefficient of Performance) = cooling output in watts divided by electrical input in watts. They are related by EER = 3.41214 x COP. An EER of 12 equals a COP of about 3.52.

How much electricity does a 1 ton AC actually use?

It depends on efficiency, not tonnage alone. Electrical input = cooling capacity / COP. A 1 ton (3.5169 kW) unit with COP 3.5 draws about 1.005 kW while running at full load; with COP 4.5 it draws about 0.78 kW. Use the EER/COP helper above with your unit's rating label to estimate yours.

What size AC do I need for my room?

A common tropical rule of thumb is about 600 BTU/hr per square meter (500 for shaded, well-insulated rooms; 700 for sun-exposed rooms or high ceilings). A 20 m² room needs roughly 12,000 BTU/hr ≈ 1 ton. This is only a rough estimate — a proper Manual J / heat-load calculation accounts for windows, occupants, and equipment.

Is 1 PK the same as 1 ton of refrigeration?

No. In Indonesia and the Netherlands, air conditioners are often sized in PK (paardekracht, metric horsepower). 1 PK ≈ 9,000 BTU/hr ≈ 2.64 kW of cooling, which is about 0.75 ton of refrigeration. So a “1 PK” AC is roughly a 3/4-ton unit, not a 1-ton unit.

Why do some sources say 3.517 kW and others 3.516 kW per ton?

They are the same value rounded differently. The full figure is 3.5168525 kW per ton of refrigeration (NIST SP 811 lists 3,516.853 W). Rounding to 3 decimals gives 3.517 kW; truncating gives 3.516 kW. The difference is under 1 watt and irrelevant for sizing.

How accurate is this converter?

Conversions are exact by definition (1 TR = 12,000 BTU/hr = 3.5168525 kW), so the math has no approximation error — only display rounding. The room-sizing helper is a rule of thumb with roughly ±20–25% uncertainty, and the EER/COP power estimate assumes steady full-load operation; real consumption varies with thermostat cycling, outdoor temperature, and part-load efficiency.

Related converters

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Ton to kW Converter

TR ⇄ kW converter

Common AC sizes: tons to kW table

AC room-sizing helper

EER / COP electricity estimator

How the number 3.5168525 is derived

Scope boundary: three different “tons”

Nearby units you may meet

Frequently asked questions

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