Dehumidifier Size Calculator
Look up a published room-condition capacity band, then check whether your room is too cold for the model you are considering.
This is the published room-condition band, not a linear square-foot calculation. Temperature triggers an operating warning; it does not add pints to this result.
- Correct bulk water before increasing capacity.
- Confirm drainage, noise, and filter access.
- Check the exact model in the CPSC recall database.
Compare current models near this capacity only after checking drainage, temperature, and recall status.
As an Amazon Associate I earn from qualifying purchases.How to use the result
The range adapts ENERGY STAR’s current guidance for portable dehumidifiers. It is a comparison starting point, not a load calculation or guarantee. Standardized capacity reflects defined test conditions; a cool basement may collect less water than the label suggests.
Classify the room
Musty is different from visible sweating or seepage. Choose the condition before looking at products.
Correct the source
Gutters, grading, leaks, and venting can matter more than another ten pints of rated capacity.
Check the system
Confirm temperature, drainage, electrical requirements, clearances, and recall status.
Primary basis: ENERGY STAR Dehumidifier Buying Guidance ↗
What this calculator actually calculates
Area and moisture condition select an ENERGY STAR planning band. Temperature does not increase the capacity result. Below 65°F the tool displays a cold-room warning; the exact model’s manual determines its operating limit.
| Room condition | Under 2,000 sq. ft. | 2,000 sq. ft. and larger |
|---|---|---|
| Slightly to moderately damp | 20–30 pints/day | 30+ pints/day |
| Very damp | 25–40 pints/day | 40+ pints/day |
| Wet | 30–50 pints/day | 50+ pints/day |
The source separates rooms smaller and larger than 2,000 square feet. At exactly 2,000 this tool uses the larger-room band as an explicit editorial boundary choice. The plus sign means the source does not provide an upper limit, not that the calculator has predicted an exact moisture load.
Worked example: one connected basement
A hypothetical 600-square-foot main room open to a 150-square-foot storage area totals 750 square feet. Selecting “very damp” gives 25–40 pints/day. Changing its temperature from 68°F to 58°F leaves that published band unchanged but adds a low-temperature warning. A closed room with poor air exchange may need its own assessment rather than being treated as equally served.
Do not use this result as a promise
The tool does not estimate gallons entering through a leak, drying time for wet building materials, air distribution, or daily electricity cost. Standing water and active seepage need source correction. Compare current ratings, not an old 80°F capacity label with a newer 65°F rating as if the test conditions were identical.
Read the sizing and purchase-specification checklist → · Diagnose a unit that runs without lowering humidity →
Rating context: ENERGY STAR testing and capacity ↗. Method checked October 10, 2026.
Your measurement record
Record the same location before and after one change. For water collection, include the unit and collection interval (for example, pints over 6 hours). Do not compare different intervals as if they were daily capacity. This blank worksheet contains your observations, not test results from Moisture Atlas.
On a small screen, scroll the table sideways to reach every field.
| Time / location | Air °F | RH % | Surface °F / water collected | Weather, equipment and wet spots |
|---|---|---|---|---|
Entries stay in this page and are not sent to our server. Download before leaving or reloading: this worksheet does not save your entries.