Convert BTU/hr to tons of refrigeration and back. Calculate HVAC cooling capacity, energy costs, and efficiency ratings for air conditioning system sizing.
The **BTU to Tons of Refrigeration Converter** helps HVAC professionals, homeowners, and engineers convert between BTU/hr and tons of refrigeration — the two most common units for measuring cooling capacity. One ton of refrigeration equals 12,000 BTU/hr, derived from the energy needed to melt one short ton (2,000 lb) of ice in 24 hours.
Whether you are sizing a residential air conditioner, specifying a commercial chiller, or comparing equipment from different manufacturers, this converter provides instant conversions with additional power units (kW, HP, kcal/hr). It also estimates operating costs based on your electricity rate and daily usage, helping you make informed purchasing decisions.
The calculator accounts for real-world system efficiency — rated BTU capacity is often higher than actual cooling delivered. By adjusting the efficiency percentage, you can estimate the true electrical power consumption and operating cost of your HVAC system. That makes it useful for comparing nameplate capacity with the practical system size and energy cost you may actually see in service. Check the example with realistic values before reporting.
HVAC equipment is often rated in BTU/hr by some manufacturers and tons by others. This converter eliminates confusion and provides all common power units in one place, plus operating cost estimates to help compare different systems.
Whether you are a homeowner comparing AC quotes, an HVAC contractor sizing ductwork, or a facility manager evaluating chillers, this tool provides the conversions and cost analysis you need for informed decisions.
Tons of Refrigeration = BTU/hr ÷ 12,000 Where: - 1 Ton of Refrigeration = 12,000 BTU/hr = 3.517 kW - 1 BTU/hr = 0.000293071 kW = 0.252164 kcal/hr - 1 HP = 2,544.43 BTU/hr - EER = BTU/hr ÷ Watts (input)
Result: 3.000 tons
A 36,000 BTU/hr air conditioner equals exactly 3 tons of refrigeration (36,000 ÷ 12,000 = 3). This is a common size for a medium residential home of 1,500-2,000 sq ft.
The BTU (British Thermal Unit) is the amount of energy needed to raise the temperature of one pound of water by one degree Fahrenheit. When rating cooling equipment, we express capacity in BTU per hour — the rate at which the system can remove heat from a space.
The ton of refrigeration has a more intuitive origin. Before mechanical refrigeration, cooling was measured by how much ice was needed. One ton of refrigeration represents the cooling effect of melting 2,000 pounds of ice in 24 hours. Since the latent heat of fusion for water is 144 BTU/lb, this works out to 2,000 × 144 / 24 = 12,000 BTU/hr.
Proper sizing requires a comprehensive load calculation (Manual J) that considers climate zone, building envelope (insulation, windows, air sealing), orientation (sun exposure), internal heat gains (people, electronics, cooking), and ventilation requirements. Online calculators can provide rough estimates, but professional calculations are recommended for equipment purchases.
Modern high-efficiency systems can achieve SEER ratings of 20 or higher, compared to older units at SEER 8-10. For a 3-ton system running 2,000 hours per year at $0.12/kWh, upgrading from SEER 10 to SEER 20 saves approximately $720 per year. Over a 15-year equipment life, that is $10,800 in savings — often exceeding the premium cost of the higher-efficiency unit.
One ton of refrigeration is the cooling capacity needed to melt one short ton (2,000 lb) of ice at 0°C in 24 hours. It equals 12,000 BTU/hr or 3.517 kW of cooling power.
A rough rule of thumb is 20-25 BTU per square foot for typical residential spaces. However, actual needs vary based on insulation, climate, sun exposure, ceiling height, and occupancy.
EER (Energy Efficiency Ratio) is measured at a single outdoor temperature (95°F). SEER (Seasonal EER) averages efficiency over an entire cooling season, giving a more realistic picture of annual performance.
No HVAC system converts 100% of electrical input to cooling. A system with a SEER of 16 is more efficient than one with SEER 10, meaning lower electricity bills for the same cooling output.
An undersized unit runs constantly without reaching target temperature. An oversized unit short-cycles, causing humidity problems and wasted energy. Professional Manual J calculations are recommended for accurate sizing.
Most single-family homes use 1.5 to 5 tons of cooling. A 1,500 sq ft home typically needs about 2.5-3 tons, while a 3,000 sq ft home may need 4-5 tons.