Sump Pump Sizing Calculator

Our sump pump sizing calculator helps determine the right pump capacity (GPM) and basin size for your basement waterproofing needs. An undersized pump can't keep up with water inflow during heavy rains, while an oversized pump short-cycles, reducing its lifespan.

The calculator considers your basement area, water table level, local rainfall rates, and discharge pipe height to estimate the required flow rate. It accounts for the pump's decreased efficiency as it pumps water higher (vertical lift) and adds a safety factor for peak events.

This tool is essential for homeowners in wet areas, those finishing basements, and anyone asking "what size sump pump do I need?" or "how big should my sump pit be?" Proper sizing prevents basement flooding and the expensive water damage that follows.