Key Conversion Factors
1 kW = 0.28435 tons = 3412.14 BTU/hr = 3.41214 MBH
1 BTU/hr = 0.000083333 tons = 0.000293 kW
1 MBH = 0.083333 tons = 0.29307 kW
Refrigeration Ton Quick Reference (1 to 25 Tons)
| Tons | BTU/hr | kW | Typical Application |
|---|---|---|---|
| 0.75 | 9 000 | 2.64 | Small mini-split, single room |
| 1.0 | 12 000 | 3.52 | Mini-split, small apartment |
| 1.5 | 18 000 | 5.28 | Condo or small home A/C |
| 2.0 | 24 000 | 7.03 | Small home central A/C |
| 2.5 | 30 000 | 8.79 | Average home central A/C |
| 3.0 | 36 000 | 10.55 | Common Canadian home size |
| 3.5 | 42 000 | 12.31 | Larger home or less-insulated home |
| 4.0 | 48 000 | 14.07 | Large home or southern Ontario climate |
| 5.0 | 60 000 | 17.58 | Very large home or small commercial |
| 7.5 | 90 000 | 26.38 | Small rooftop unit |
| 10 | 120 000 | 35.17 | Small commercial rooftop unit |
| 12.5 | 150 000 | 43.96 | Medium commercial unit |
| 15 | 180 000 | 52.75 | Commercial rooftop / AHU |
| 20 | 240 000 | 70.34 | Small air-cooled chiller |
| 25 | 300 000 | 87.92 | Small chiller or large RTU |
Commercial Chiller Capacity Reference (30 to 1000 Tons)
| Tons | BTU/hr | kW | Chiller Type / Application |
|---|---|---|---|
| 30 | 360 000 | 105.5 | Small air-cooled scroll chiller |
| 50 | 600 000 | 175.8 | Mid-size air-cooled chiller |
| 75 | 900 000 | 263.8 | Common office building chiller |
| 100 | 1 200 000 | 351.7 | Standard air-cooled chiller size |
| 150 | 1 800 000 | 527.5 | Large air-cooled chiller |
| 200 | 2 400 000 | 703.4 | Small water-cooled centrifugal |
| 300 | 3 600 000 | 1055 | Medium hospital or campus chiller |
| 500 | 6 000 000 | 1758 | Large water-cooled centrifugal |
| 750 | 9 000 000 | 2638 | Large institutional / district cooling |
| 1000 | 12 000 000 | 3517 | Central plant / district cooling |
How to Use the Tons to BTU/hr Converter
Type a cooling capacity in tons, BTU/hr, kW, watts, or MBH. All other units update instantly. Use the quick presets for common residential sizes (1.5 to 5 tons) and commercial sizes (10 to 100 tons), or load the most common chiller size (100 ton) for a reference starting point.
The result panel identifies what class of HVAC equipment your capacity value corresponds to: mini-split, residential central A/C, light commercial rooftop, commercial chiller, or central plant. This helps verify your converted value is in the right order of magnitude before using it in equipment selection or electrical sizing.
Two reference tables cover 1 to 25 tons for residential and light commercial applications, and 30 to 1000 tons for commercial chiller plants. Use these to identify the standard equipment size closest to your calculated load and to verify BTU/hr and kW equivalents for submittal documents and electrical sizing.
Always base equipment selection on a proper cooling load calculation, not rules of thumb. Use the Cooling Load Calculator for your building's peak cooling load in BTU/hr or kW, then convert to tons here to identify the standard equipment size. For efficiency comparison, use the SEER / COP / HSPF Converter and COP / EER Converter.
Tons of Refrigeration -- Complete Guide for Canadian HVAC
The ton is a uniquely North American capacity unit that dates from the era of ice cooling. ASHRAE's official terminology defines one ton of refrigeration as the rate of heat removal equal to melting one short ton (2000 lb) of ice over 24 hours. The calculation: 2000 lb x 144 BTU/lb latent heat of fusion / 24 hours = 12 000 BTU/hr = 3.517 kW. Despite being an archaic unit, tons remain the dominant language for describing cooling capacity in North American HVAC, from residential mini-splits to large chiller plants.
Converting Tons to kW for Canadian Engineering
Canadian engineering specifications, electrical sizing, and energy analysis all use kilowatts. The conversion is straightforward: 1 ton = 3.51685 kW, or 1 kW = 0.28435 tons. A 3-ton residential air conditioner delivers 10.55 kW of cooling capacity. A 100-ton chiller delivers 351.7 kW. Note that this is cooling capacity -- the heat removed from the conditioned space. Electrical input power is different and depends on equipment efficiency (EER, COP). For the complete power conversion tool covering kW, BTU/hr, HP, and MBH, use the Power Converter.
Residential Air Conditioning Sizing in Canada
Most Canadian detached homes require between 1.5 and 5 tons (5.28 to 17.58 kW) of cooling capacity. The correct size depends on floor area, insulation levels, window area and orientation, ceiling height, local design temperatures, and internal gains. A well-insulated 150 m² (1615 ft²) home in Toronto with low window-to-wall ratio might need only 2 to 2.5 tons (7 to 8.8 kW) for cooling. The same floor area in a less-insulated older home with lots of south-facing glass might need 3 to 3.5 tons (10.5 to 12.3 kW). Oversizing air conditioners causes short cycling, poor dehumidification, and comfort complaints -- especially in humid Ontario and Quebec summers. Always base residential equipment sizing on a CSA F280 cooling load calculation. Use the Cooling Load Calculator for a full analysis.
MBH for Commercial HVAC
MBH (thousands of BTU per hour) is common in commercial HVAC for both heating and cooling capacity. 1 MBH = 1000 BTU/hr. A 100-ton chiller delivers 1200 MBH of cooling. A 300 MBH commercial boiler delivers 300 000 BTU/hr (87.9 kW) of heating output. Commercial submittal documents often use MBH because the numbers are easier to read than full BTU/hr figures at large capacity scales. When translating between MBH on a Canadian submittal and kW on an electrical drawing, multiply MBH by 0.293 to get kW, using the exact BTU-to-watt factor set out in the NIST Guide to the SI, Appendix B.
Tons of Heat Rejection
Cooling towers and condensers are sized in tons of heat rejection -- not refrigeration tons. Heat rejection equals cooling capacity plus compressor heat input. For a water-cooled chiller with COP 5.0 delivering 100 tons of cooling, compressor input = 100 tons / COP = 100 / 5.0 = 20 tons of electrical heat equivalent. Total heat rejection = 100 + 20 = 120 tons. A cooling tower for this chiller must reject 120 tons (422 kW), not just the 100 tons of cooling capacity, which the Cooling Tower Calculator accounts for directly. Always clarify whether a tonnage specification refers to refrigeration tons or condenser/heat rejection tons when selecting cooling towers, condensers, and fluid coolers.
Frequently Asked Questions
One ton of refrigeration equals exactly 12 000 BTU/hr or 3.517 kW. This is an exact relationship: 1 ton = 12 000 BTU/hr with no rounding. A 2-ton residential A/C delivers 24 000 BTU/hr (7.03 kW), a 3-ton delivers 36 000 BTU/hr (10.55 kW), and a 5-ton delivers 60 000 BTU/hr (17.58 kW). Enter any value in the converter above and all five units update instantly.
Multiply tons by 3.51685 to get kW. So 1 ton = 3.517 kW, 5 tons = 17.58 kW, and 100 tons = 351.7 kW. To go the other direction, divide kW by 3.51685. This is the most common conversion in Canadian commercial HVAC since equipment is specified in tons but electrical sizing, energy analysis, and Canadian engineering documents use kW. For the full power conversion tool, use the Power Converter.
Most Canadian homes need between 1.5 and 5 tons (18 000 to 60 000 BTU/hr) of cooling capacity. A well-insulated 150 m² home in Toronto might need 2 to 2.5 tons; a larger 250 m² home or one with more glazing might need 3 to 4 tons. Rules of thumb are a starting point only -- equipment sizing should be based on a proper CSA F280 cooling load calculation using your specific home's envelope, orientation, and local design temperatures. Oversized equipment short-cycles and dehumidifies poorly. Use the Cooling Load Calculator for a proper analysis.
Tons of refrigeration measures cooling capacity -- heat removed from the conditioned space. Tons of heat rejection measures the total heat dumped at the condenser, which equals cooling capacity plus compressor heat input. For a chiller with COP 5.0 delivering 100 refrigeration tons, compressor input equals 100/5.0 = 20 equivalent tons of electrical heat. Total heat rejection = 120 tons. Cooling towers and condensers are sized for heat rejection tons, not refrigeration tons. Always clarify which ton is specified when ordering condensers, cooling towers, or fluid coolers.