Basement and crawl space decisions come down to a few numbers: how much water a pit holds, how many pints of moisture a dehumidifier must remove, how much liner a crawl space needs and whether a window meets the escape code. These tools work them out and show the formula and the source behind each.
All basement calculators
Sump Pump Size
Sump pump size calculator: enter pit size, pump flow at its lift and the time between cycles to see run time, cycles per hour and the horsepower rule.
Dehumidifier Size
Dehumidifier size calculator: pick how damp the space is and its floor area to get the ENERGY STAR range in pints per day, plus old-to-new rating conversion.
Crawl Space Liner Material
Crawl space vapor barrier calculator: enter the floor size, wall and pier laps and seam overlap to get liner area, rolls and the length of seams to seal.
Egress Window Size
Egress window size calculator: enter the clear opening, sill height and window well to check the 5.7 sq ft, 24 by 20 inch, 44 inch and 9 sq ft code rules.
Start with the tool that matches your problem: water in the pit, damp air, a bare crawl space floor or a basement bedroom window.