Garbage Disposal Sizing Calculator

No — Septic System only sets a separate Septic-Compatible Needed flag recommending a septic-assist model with enzyme injection; it does not add to the Usage Intensity Score and has zero effect on Recommended HP, Estimated Amps, Chamber Size, or Price Range. If you're on a septic system, treat the septic flag as an additional shopping criterion on top of — not a change to — the HP recommendation from household size, cooking frequency, and hard foods.

Household Size and Cooking Frequency actually tie for the widest scoring range — Household Size spans 1 to 4 points across its four tiers (a 3-point range) and Cooking Frequency spans 0 to 3 points directly from its own value (also a 3-point range); neither one contributes more raw points than the other. Hard Foods isn't a range at all — it's a fixed, all-or-nothing 2-point jump when toggled on, which can be enough by itself to push the recommendation up a full HP tier. A large household that cooks daily and also grinds bones and shells regularly can jump from a 1/3 HP light-use recommendation to a 3/4 HP or larger recommendation.

Estimated Amps, Motor RPM, Chamber Size, and Price Range are all looked up from the Recommended HP tier the scoring model lands on — they aren't calculated independently from your household size, cooking frequency, or food type inputs. Once the HP tier is determined, these downstream figures follow automatically as typical specifications for that tier.

Batch Feed Recommended flags as 1 when your household has 3 or more people AND you've toggled Hard Foods on — the idea being that a batch-feed disposal (which requires a stopper in place before it will run) is a safer choice around children or larger households that grind riskier hard waste, compared to a continuous-feed unit that runs the moment it's switched on.