Refrigeration Tons to BTU per Hour Converter
Convert cooling capacity between refrigeration tons and BTU per hour (BTU/hr). Bidirectional, supports multiple tons definitions, and shows the full formula with worked examples.
Tons of Refrigeration ⇄ BTU per Hour
From Tons to BTU/hr
Change the definition if you are working with metric or historical data.
From BTU/hr to Tons
Use the same definition as the system or datasheet you are converting from.
Result (from Tons)
BTU/hr: –
Result (from BTU/hr)
Tons: –
Formula to convert refrigeration tons to BTU per hour
In HVAC, a ton of refrigeration is a unit of cooling power historically based on the heat required to melt one short ton (2,000 lb) of ice over 24 hours. In modern practice:
Standard US definition
\( 1 \text{ ton of refrigeration} = 12{,}000 \ \text{BTU/hr} \)
Conversion formula
\( \text{BTU/hr} = \text{tons} \times 12{,}000 \)
Example: 3 tons to BTU/hr
Suppose you have a 3-ton air conditioner and want to know its cooling capacity in BTU/hr.
\( \text{BTU/hr} = 3 \times 12{,}000 = 36{,}000 \ \text{BTU/hr} \)
So a 3-ton AC unit provides approximately 36,000 BTU/hr of cooling capacity.
Formula to convert BTU per hour to refrigeration tons
To go the other way, divide the BTU/hr value by 12,000:
\( \text{tons} = \dfrac{\text{BTU/hr}}{12{,}000} \)
Example: 30,000 BTU/hr to tons
\( \text{tons} = \dfrac{30{,}000}{12{,}000} = 2.5 \ \text{tons} \)
Other ton definitions (metric & historical)
While 12,000 BTU/hr is the standard in North America, you may encounter other definitions:
- Metric refrigeration ton: 3,024 kcal/hr ≈ 11,959 BTU/hr
- ASHRAE historical ton: ≈ 12,660 BTU/hr (based on more precise ice-melting calculations)
This converter lets you choose between these definitions so you can match the standard used in your datasheets, design codes, or regional practice.
Quick reference table (US tons ↔ BTU/hr)
| Tons | BTU/hr |
|---|---|
| 0.5 | 6,000 |
| 1 | 12,000 |
| 1.5 | 18,000 |
| 2 | 24,000 |
| 2.5 | 30,000 |
| 3 | 36,000 |
| 4 | 48,000 |
| 5 | 60,000 |
| 10 | 120,000 |
When to use tons vs BTU/hr in HVAC work
Both units describe cooling capacity, but they are used in slightly different contexts:
- Tons – common in HVAC equipment sizing (e.g., 2-ton, 3-ton residential AC units).
- BTU/hr – common in engineering calculations, load calculations, and detailed specifications.
For example, a residential load calculation might show a required capacity of 28,500 BTU/hr. Dividing by 12,000 gives about 2.38 tons, so you would likely choose a 2.5-ton unit, then refine based on manufacturer performance data.
Common pitfalls and tips
- Do not confuse BTU with BTU/hr. BTU is energy; BTU/hr is power (rate of heat transfer).
- Check the ton definition. For most HVAC work in the US and Canada, 1 ton = 12,000 BTU/hr.
- Consider sensible vs latent loads. The ton rating is total capacity; actual sensible cooling may be lower.
- Use proper load calculations. Rules of thumb (tons per square foot) are only rough starting points.