actonnagecalc.com is a set of free, browser-based air conditioner sizing tools. Every calculator runs entirely in your browser — your room dimensions, locations and inputs are never uploaded anywhere.
The site exists because "what size AC do I need?" gets two very different answers depending on where you live. A US home sizes a central system for the whole envelope; an Indian home sizes a split AC per room against far harsher solar loads. Most calculators online silently assume one or the other. Ours handles both, and detects your region automatically (you can always switch with the US/India toggle in the header).
The load model follows Manual J-style factors: climate-zone BTU rates, ceiling-height multipliers, sun exposure, insulation quality, top-floor roof gain, occupancy and window counts. Indian electricity estimates use BEE ISEER bands; US estimates use SEER2. Full formulas are documented across the guides.
These are estimates for planning and sanity-checking quotes — final equipment sizing for a central system should always come from a licensed contractor's Manual J calculation.
Built and maintained by Murugan Vellaichamy. Corrections, bug reports and suggestions are welcome: contactus@actonnagecalc.com.