🔄 Sump Pump Size Calculator
📐 sump pump size calculator — correctly sizing your sump pump prevents flooding, protects foundations, and ensures reliability worldwide. This advanced tool follows global hydrology standards (ASCE, ISO, and typical building codes) while adapting to local rainfall intensities, drainage area, and groundwater inflow. Get accurate pump capacity in GPM (US) or L/min (metric) with recommendations based on vertical lift and safety margins. Designed for residential, commercial & industrial use across all countries.
sq ft (ft²)
inches per hour (in/hr)
(0 = no runoff, 1 = total runoff)
gallons per minute (GPM)
feet (ft)
(minimum 1.0, 1.2 standard)
⚙️ REQUIRED PUMP CAPACITY
— GPM
— L/min
🛠️ Recommended Sump Pump (Worldwide standards)
—
📈 ADVANCED CHART: Required Flow vs Rainfall Intensity
Based on current area, runoff, and base inflow — shows pump demand increase with storm severity
📌 Design standards & factor insights (USA / Global)
🇺🇸 EPA Rainfall: 1-2 in/hr design storm
🌍 ISO 6182: runoff coefficient 0.7-0.95
🏠 Residential average: 30-40 GPM @ 10ft head
💡 Vertical lift reduces output ~10% per 5ft extra
📖 Runoff coefficient: Concrete/roof 0.9–1.0, gravel 0.5–0.7. Rainfall intensity use 100-year data for high risk zones. Additional inflow measured from spring or high water table. For European/Asian standards: 300 mm/hr peak may occur; our calculator adapts units and safety margin.