On the outdoor unit's data plate, read the model number (not the serial). A two-digit group from 18, 24, 30, 36, 42, 48, 60 is the capacity in thousands of BTU: GSX140241K → 24,000 BTU → 2 tons. Our decoder applies the exact nomenclature for 22 brands. Indian split ACs often print tonnage directly in the model name (1.5T) or use the 12/18/24 BTU codes.
Some plates list rated cooling capacity in BTU/hr or kW directly. 17,580 W of cooling? That's 5 tons (×3.517 kW per ton). kcal/hr figures divide by ~3,024 per ton.
If the model is illegible, the compressor's RLA (Rated Load Amps) gives a rough bracket: modern condensers run very approximately 5–7 RLA per ton at 240 V. A plate showing RLA 19 suggests ~3 tons. Treat this as a last-resort estimate; verify with the manufacturer using the serial number if possible.
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No — serials encode manufacture date and plant, not capacity. Use the model number.
3 tons exactly — divide BTU by 12,000.
Put the numbers to work: AC tonnage calculator · bill calculator · model number decoder.