Length × width of the space you want to dry.

How damp is the space?
Extra moisture sources (optional)

How this calculator works

The recommendation interpolates the AHAM sizing chart (300–3,000 sq ft breakpoints) under the post-2019 DOE test standard. Effective area is scaled for ceiling height using AHAM's published multipliers (a 10-ft ceiling is ×1.25), and 5 pints of headroom are added per constant moisture source — indoor laundry drying, or a below-grade location where soil moisture never stops. When a result lands between retail sizes, we round up — an oversized unit cycles off; an undersized one runs forever and never catches up.