Sump pump sizing Last reviewed June 2026
What Size Sump Pump for a Basement? Complete Guide
By the WhatSize editorial team 4 min read Standards-reviewed
Most residential basements need a 1/2 HP sump pump. For light seepage, 1/3 HP works. For heavy water or deep pits (36+ inches), 3/4 HP is recommended.
Basement Sump Pump Sizing Depends on Water Volume
The right sump pump for your basement depends on how much water you need to move and how high it needs to go. A 1/2 HP pump like the Superior Pump 92341 handles 3,600 GPH at 10 ft of head — enough for the vast majority of basement applications.
Top picks for this size
These Amazon-available picks meet the calculated spec. For region-specific or licensed contractor-installed options, consult a local professional. See our Disclaimers.
Sump Pump Sizing by Basement Condition
- Light seepage (pit under 24"): 1/3 HP — Wayne CDU33 (~$89)
- Moderate moisture (pit 18-30"): 1/2 HP — Superior Pump 92341 (~$119)
- Heavy water (pit 30"+): 3/4 HP — Zoeller M98 (~$249)
Frequently asked questions
What size sump pump do I need for my basement?
Submersible pumps sit inside the sump pit, are quieter, and more powerful. Pedestal pumps sit above the pit on a pole — cheaper but louder. For basements, submersible is the better choice.
Do I need a backup sump pump?
If you have a finished basement, a battery backup system is strongly recommended. It kicks in during power outages, which often coincide with the worst storms.
How often should I replace my sump pump?
Most sump pumps last 5-10 years. If your pump is more than 7 years old or making unusual noises, consider replacing it before failure occurs.