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Ton of Refrigeration to Electric Horsepower Converter

Convert TR to hp(E) with our free online power converter.

Quick Answer

1 Ton of Refrigeration = 4.71428 hp(E)

Formula: Ton of Refrigeration × conversion factor = Electric Horsepower

Use the calculator below for instant, accurate conversions.

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All conversion formulas on UnitsConverter.io have been verified against NIST (National Institute of Standards and Technology) guidelines and international SI standards. Our calculations are accurate to 10 decimal places for standard conversions and use arbitrary precision arithmetic for astronomical units.

Last verified: February 2026Reviewed by: Sam Mathew, Software Engineer

Ton of Refrigeration to Electric Horsepower Calculator

How to Use the Ton of Refrigeration to Electric Horsepower Calculator:

  1. Enter the value you want to convert in the 'From' field (Ton of Refrigeration).
  2. The converted value in Electric Horsepower will appear automatically in the 'To' field.
  3. Use the dropdown menus to select different units within the Power category.
  4. Click the swap button (⇌) to reverse the conversion direction.
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How to Convert Ton of Refrigeration to Electric Horsepower: Step-by-Step Guide

Converting Ton of Refrigeration to Electric Horsepower involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

hp(E) = TR × 4.71428

Example Calculation:

1 TR = 4.71428 hp(E)

Disclaimer: For Reference Only

These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.

Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.

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What is a Ton of Refrigeration and a Electric Horsepower?

1 ton of refrigeration (TR) = 12,000 BTU/h = 3.517 kW = 3,024 kcal/h

Origin: Heat absorbed by melting 1 ton (2,000 lbs) of ice at 32°F in 24 hours

1 hp(E) = 746 W = 0.746 kW = 1.0004 hp (mechanical) = 2,545 BTU/h

Difference from mechanical hp: 746 W vs 745.7 W (0.04% higher)

Note: The Ton of Refrigeration is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Electric Horsepower belongs to the imperial/US customary system.

Common Uses and Applications: TR vs hp(E)

Explore the typical applications for both Ton of Refrigeration (imperial/US) and Electric Horsepower (imperial/US) to understand their common contexts.

Common Uses for TR

Residential AC: Home air conditioning systems (1.5-5 tons typical). Commercial HVAC: Office buildings, retail (10-200 tons per system). Industrial Refrigeration: Cold storage, food processing (50-500+ tons). Chiller Systems: Large building cooling, data centers.

When to Use hp(E)

Electric Motors: Industrial motors, pumps, compressors (ratings in hp(E)). HVAC: Fan motors, blower motors (fractional to 10 hp). Manufacturing: Conveyor motors, machine tools (1-100 hp). Residential: Garage door openers, pool pumps (0.5-3 hp).

Additional Unit Information

About Ton of Refrigeration (TR)

How many tons of AC do I need?

Basic calculation: Square footage ÷ 400-600 = tons needed

More accurate method:

  1. Calculate BTU/h needed (sq ft × 20-25 BTU/h)
  2. Divide by 12,000 to get tons

Example (1,800 sq ft home):

  • BTU/h needed: 1,800 × 22 = 39,600 BTU/h
  • Tons needed: 39,600 ÷ 12,000 = 3.3 tons
  • Choose: 3 ton or 3.5 ton system

Factors affecting sizing:

  • Climate zone (hot = more, moderate = less)
  • Insulation quality
  • Window area and orientation
  • Ceiling height
  • Number of occupants
  • Heat-generating appliances

[AC sizing calculator]

How do I convert tons to BTU/h or kW?

Formulas:

  • BTU/h = Tons × 12,000
  • kW = Tons × 3.517

Examples:

  • 2 tons = 24,000 BTU/h = 7.03 kW
  • 3 tons = 36,000 BTU/h = 10.55 kW
  • 4 tons = 48,000 BTU/h = 14.07 kW
  • 5 tons = 60,000 BTU/h = 17.58 kW

Reverse:

  • BTU/h ÷ 12,000 = Tons
  • kW ÷ 3.517 = Tons

Tons to BTU/h converter → Tons to kW converter →

Why is it called a "ton" of refrigeration?

Historical origin: In the 1800s, ice production was measured by tons of ice produced.

The definition: 1 ton of refrigeration = cooling power needed to freeze 1 ton (2,000 pounds) of water at 32°F into ice in 24 hours.

The math:

  • Latent heat of ice: 144 BTU per pound
  • 2,000 lbs × 144 BTU/lb = 288,000 BTU in 24 hours
  • 288,000 BTU ÷ 24 hours = 12,000 BTU/h

Modern usage: The unit stuck even though we no longer use ice for cooling. It's purely a power measurement, NOT a weight!

What size AC for 2000 sq ft?

Typical: 3-4 tons (36,000-48,000 BTU/h)

Calculation (using 20 BTU/h per sq ft):

  • 2,000 sq ft × 20 = 40,000 BTU/h
  • 40,000 ÷ 12,000 = 3.33 tons
  • Result: 3-ton or 3.5-ton system

Climate adjustments:

  • Hot climate (Arizona, Florida): 4 tons (higher load)
  • Moderate climate: 3-3.5 tons
  • Cool climate (Northern states): 2.5-3 tons

Other factors:

  • Well-insulated home: Can use smaller (3 tons)
  • Poor insulation, lots of windows: Need larger (4 tons)
  • High ceilings: Add 10-20%
  • Multiple stories: May need multiple smaller units

Is bigger better for AC tonnage?

NO! Oversizing causes problems:

Issues with oversized AC:

  • Short cycling: Turns on/off frequently, wears out faster
  • Poor dehumidification: Doesn't run long enough to remove humidity
  • Hot/cold spots: Uneven cooling
  • Higher energy bills: Inefficient operation
  • Shorter lifespan: More wear and tear

Ideal sizing: AC should run 15-20 minutes per cycle, cycling 2-3 times per hour on hot days

Example:

  • 1,500 sq ft home needs 2.5-3 tons
  • Installing 5 tons would be wasteful and problematic
  • Better to size correctly or slightly undersize than oversize

About Electric Horsepower (hp(E))

How do I convert electric horsepower to watts?

Formula: W = hp(E) × 746

Examples:

  • 1 hp(E) = 746 W
  • 5 hp(E) = 3,730 W = 3.73 kW
  • 10 hp(E) = 7,460 W = 7.46 kW
  • 0.5 hp(E) = 373 W

Electric HP to Watts converter →

What is the difference between electric and mechanical horsepower?

Electric HP (hp(E)): 746 W exactly (US electric motors) Mechanical HP (hp): 745.7 W (550 ft⋅lb/s, automotive standard)

Difference: 0.04% (practically identical)

Usage:

  • Electric motors → hp(E)
  • Engines (gas, diesel) → mechanical hp
  • International → kW preferred

Conversion: 1 hp(E) = 1.0004 hp (mechanical)

How much power does a 1 hp electric motor use?

Full load: 746 W input (if 100% efficient)

Realistic power draw (accounting for efficiency):

  • 50% efficiency: 1,492 W (1.5 kW)
  • 70% efficiency: 1,066 W (1.07 kW)
  • 85% efficiency: 878 W (0.88 kW)
  • 90% efficiency: 829 W (0.83 kW)

Example: 1 hp motor at 85% efficiency draws 878W. Running 8 hours = 7 kWh energy consumed.

Modern motors: 85-95% efficient. Older motors: 70-85%.

Why use hp(E) instead of kW?

US tradition: Motor industry established before SI metric adoption

Current practice:

  • US: Both hp(E) and kW used (hp(E) more common for small motors)
  • Europe/Asia: Primarily kW
  • International standards: Moving toward kW only

Nameplate labeling: Many US motors show both (e.g., "1 hp / 0.75 kW")

Conversion: Divide hp(E) by 1.341 to get kW

How do I size a motor for my application?

Basic formula: Required hp = (Torque × RPM) ÷ 5,252

Practical approach:

  1. Determine load requirements (torque, speed, duty cycle)
  2. Add safety factor: Multiply by 1.15-1.25 (15-25% margin)
  3. Select next standard size: 1/4, 1/3, 1/2, 3/4, 1, 1.5, 2, 3, 5, 7.5, 10 hp

Example: Application needs 0.8 hp → Add 25% = 1 hp → Select 1 hp motor

Avoid oversizing: Wastes energy, motors run inefficiently at low load.

Conversion Table: Ton of Refrigeration to Electric Horsepower

Ton of Refrigeration (TR)Electric Horsepower (hp(E))
0.52.357
14.714
1.57.071
29.429
523.571
1047.143
25117.857
50235.714
100471.428
2501,178.57
5002,357.14
1,0004,714.28

People Also Ask

How do I convert Ton of Refrigeration to Electric Horsepower?

To convert Ton of Refrigeration to Electric Horsepower, enter the value in Ton of Refrigeration in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our power converter page to convert between other units in this category.

Learn more →

What is the conversion factor from Ton of Refrigeration to Electric Horsepower?

The conversion factor depends on the specific relationship between Ton of Refrigeration and Electric Horsepower. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.

Can I convert Electric Horsepower back to Ton of Refrigeration?

Yes! You can easily convert Electric Horsepower back to Ton of Refrigeration by using the swap button (⇌) in the calculator above, or by visiting our Electric Horsepower to Ton of Refrigeration converter page. You can also explore other power conversions on our category page.

Learn more →

What are common uses for Ton of Refrigeration and Electric Horsepower?

Ton of Refrigeration and Electric Horsepower are both standard units used in power measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our power converter for more conversion options.

For more power conversion questions, visit our FAQ page or explore our conversion guides.

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Verified Against Authority Standards

All conversion formulas have been verified against international standards and authoritative sources to ensure maximum accuracy and reliability.

NIST Reference on Constants, Units and Uncertainty

National Institute of Standards and Technology — Fundamental physical constants and unit conversions

BIPM SI Units

Bureau International des Poids et Mesures — International System of Units (SI) definitions and standards

ISO 80000

International Organization for Standardization — Quantities and units international standards series

Last verified: February 19, 2026