How many BTU are in a ton of cooling?

One ton of refrigeration equals 12,000 BTU/h, which is approximately 3.517 kW. So a 2.5-ton system is 30,000 BTU/h.

How do you convert EER to COP?

COP = EER ÷ 3.412. The 3.412 factor converts BTU/h to watts. For example, an EER of 12 is a COP of about 3.52.

How do you convert SEER to EER?

There is no exact conversion because SEER is a seasonal average and EER is a single rating point, but a common field approximation is EER ≈ 0.875 × SEER (older rule) — manufacturer performance data is always preferred over any rule of thumb.

How do you convert PSI to kPa?

Multiply PSI by 6.895 to get kPa (1 PSI = 6.895 kPa). To go the other way, divide kPa by 6.895.

HVAC Unit Converter

Free HVAC unit converter for technicians. Convert tons, BTU/h, and kW; Fahrenheit and Celsius; SEER, EER, and COP; PSI and kPa; and pounds and kilograms — all in one place.

Capacity: Tons ↔ BTU/h ↔ kW

Temperature: °F ↔ °C

Efficiency: EER ↔ COP

Pressure: PSI ↔ kPa

Weight: lb ↔ kg

Common HVAC unit conversions

This converter bundles the everyday unit conversions an HVAC tech reaches for, using standard factors:

Conversion	Factor
Capacity	1 ton = 12,000 BTU/h = 3.517 kW
Temperature	°F = °C × 9/5 + 32 · °C = (°F − 32) × 5/9
Efficiency	COP = EER ÷ 3.412 (EER = COP × 3.412)
Pressure	1 PSI = 6.895 kPa
Weight	1 lb = 0.4536 kg

Notes on efficiency ratings

EER is a single-point rating (95°F outdoor) and COP is a dimensionless ratio of output to input — they convert exactly with the 3.412 BTU/h-per-watt factor.
SEER is a seasonal average and does not convert exactly to EER. Field rules of thumb exist, but always use the manufacturer’s published performance data for real numbers.

Need to size airflow or capacity instead of just converting units? Use the CFM & Tonnage Calculator.

How FieldPad helps in the field

Convert on the spot here, then keep the job moving in FieldPad — log equipment specs, refrigerant weights, and capacities against the client and the system, and turn them straight into estimates and invoices. One offline-ready app, no re-keying, full history on every piece of equipment.