Dehumidifier Size Calculator

Enter the room area and how damp it honestly is - musty smell, window condensation, or mold spots. The calculator gives the pints-per-day rating to buy, the running watts, and what ten hours a night costs on your bill.

The rating on the box assumes a specific lab room, and basements cheat. This one scales by area and dampness, points at the 40-50 percent humidity target where mold stops and sinuses survive, and explains the window-condensation signal that winter sends every morning.

–pints per day rating
–running watts, typical
–cost per month at 10 h/day
–target humidity

How to use

  1. Measure the room, not the floor plan - the machine dehumidifies one space.
  2. Rate the dampness honestly; mold spots mean the top bracket.
  3. Basements and bathrooms take one size up from the number.

Frequently asked questions

What size dehumidifier do I need for my room?

Industry ratings run about 8 pints per day for slightly damp 500 square feet, up to 16 for very damp. The calculator scales to your area and dampness - and basements deserve the next size up.

What humidity should I set my dehumidifier to?

40 to 50 percent relative humidity. Above 50 the mold and dust mites feed; below 40, wood cracks and throats complain. A unit with a humidistat stops at the target instead of running forever.

Why is my bedroom window wet in the morning?

Warm indoor air holds moisture that condenses on the cold glass overnight - breathing, drying clothes and cooking all feed it. Ventilation helps at the source; a dehumidifier closes the gap in the dampest room.

Do dehumidifiers use a lot of electricity?

A typical room unit draws 200-400 watts - about the same as the fridge it sits next to. Run ten hours a night and the calculator prices it; the humidistat keeps the real bill lower by coasting at the target.

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