BTU / Tonnage Converter (HVAC)

Convert between BTU/hr and refrigeration tons — the two most common ways HVAC capacity is stated on equipment nameplates and load calculations.

How it works

1 refrigeration ton = 12,000 BTU/hr (heat required to melt one short ton of ice in 24 hours). BTU to tons: tons = BTU / 12,000. Tons to BTU: BTU = tons x 12,000.

Worked example

A 24,000 BTU/hr window unit: 24,000 / 12,000 = 2 tons. Conversely, a 3-ton central system: 3 x 12,000 = 36,000 BTU/hr.

When to use it

Refrigeration ton is a rate (power), not a weight — it is equivalent to about 3.517 kW.
Residential systems are typically sized 1 to 5 tons; commercial rooftop units can run 20+ tons.
This conversion is exact — no rounding factors apply. Sizing a system requires a proper Manual J load calculation; capacity alone does not guarantee comfort.
Equipment nameplates often use BTU/hr while contractors quote ton capacity — this tool bridges the gap quickly.

Related calculators

All results are an engineering estimate — not for custody transfer. Field measurement and certified tables govern.