How do you convert BTU to HP?

To convert BTU/hr to horsepower, divide the BTU/hr value by 2,545. For example: 12,000 BTU/hr ÷ 2,545 = 4.71 HP. To convert HP to BTU/hr, multiply by 2,545. For example: 5 HP × 2,545 = 12,725 BTU/hr.

What is the difference between mechanical HP and electrical HP?

Mechanical horsepower (550 ft·lbf/s) equals 2,544.43 BTU/hr and is used for engines and motors. Electrical horsepower (746 watts) equals 2,545.46 BTU/hr and is more commonly used in HVAC. The difference is less than 0.1%, so for most practical purposes they are interchangeable.

How many BTU is a 5 HP motor?

A 5 HP motor produces approximately 12,725 BTU/hr of heat output (5 × 2,545 = 12,725). This is important for calculating cooling loads in mechanical rooms and equipment spaces where motor heat must be accounted for in the HVAC design.

BTU to HP Converter

Convert BTU per hour to horsepower and HP to BTU/hr. Used for HVAC sizing, motor calculations, and heating system design.

1 HP = 2,545 BTU/hr | 1 BTU/hr = 0.000393 HP

BTU/hr ↔ Horsepower Calculator

BTU per hour (BTU/hr)

Horsepower (HP)

Quick conversions:

BTU to HP Conversion Table

BTU/hr	Horsepower (HP)	Tons	Typical Application
6,000	2.36	0.5	Window AC unit
12,000	4.71	1	Small room AC, mini-split
18,000	7.07	1.5	Large room / studio
24,000	9.43	2	Small apartment
36,000	14.14	3	Average home
48,000	18.86	4	Large home
60,000	23.57	5	Large home / small commercial
80,000	31.43	6.67	Furnace / commercial
100,000	39.29	8.33	Commercial HVAC
120,000	47.14	10	Large commercial

BTU to HP Conversion Formula

BTU/hr to HP

HP = BTU/hr ÷ 2,545

Example: 36,000 BTU/hr ÷ 2,545 = 14.15 HP

HP to BTU/hr

BTU/hr = HP × 2,545

Example: 10 HP × 2,545 = 25,450 BTU/hr

Types of Horsepower

Mechanical HP (imperial HP)

1 HP = 550 ft·lbf/s = 2,544.43 BTU/hr

Used for: engines, pumps, compressors

Electrical HP

1 HP = 746 W = 2,545.46 BTU/hr

Used for: electric motors, HVAC equipment

When You Need BTU to HP Conversion

HVAC Sizing

Compare equipment rated in BTU/hr with motor requirements in HP. Size compressors and blower motors for air conditioning systems.

Heating Systems

Convert furnace or boiler output (BTU/hr) to equivalent horsepower for pump and fan motor sizing in hydronic heating.

Motor Heat Load

Calculate how much heat a motor generates in BTU/hr for mechanical room cooling load calculations.

Frequently Asked Questions

How many BTU is 1 HP?

1 horsepower equals 2,545 BTU per hour (BTU/hr). More precisely, 1 mechanical HP = 2,544.43 BTU/hr and 1 electrical HP = 2,545.46 BTU/hr. For most HVAC and plumbing calculations, 2,545 BTU/hr per HP is the standard conversion factor.

How many HP is 36,000 BTU?

36,000 BTU/hr equals approximately 14.15 HP. This is equivalent to 3 tons of cooling capacity — a common residential air conditioning size. To calculate: 36,000 ÷ 2,545 = 14.15 HP.

How many HP is 12,000 BTU?

12,000 BTU/hr equals approximately 4.71 HP. This is exactly 1 ton of refrigeration — the standard unit for air conditioning capacity. A 1-ton mini-split or window unit produces 12,000 BTU/hr of cooling.

Is BTU to HP the same as BTU to boiler horsepower?

No. Boiler horsepower (BHP) is a different unit: 1 BHP = 33,475 BTU/hr, which is about 13 times larger than mechanical HP. Boiler HP measures steam generation capacity, not mechanical power. This converter uses mechanical/electrical HP (2,545 BTU/hr).

How do I convert BTU to HP for a furnace?

Divide the furnace BTU/hr rating by 2,545. For example, an 80,000 BTU/hr furnace = 31.4 HP equivalent. Note that furnace ratings are usually input BTU — multiply by efficiency (e.g., 0.95 for 95% AFUE) to get actual output before converting.

Why do HVAC systems use both BTU and HP?

BTU/hr measures thermal energy output (heating/cooling capacity) while HP measures mechanical power (motor size). An AC system has a cooling capacity in BTU/hr but its compressor motor is rated in HP. These are different measurements of the same system — capacity vs. power consumption.