Rodent Bait Station Calculator
Determine how many exterior and interior bait stations you need based on building perimeter, interior size, and infestation severity.
About this calculator
This calculator estimates exterior and interior rodent bait station counts from building perimeter, interior square footage, and infestation severity. Exterior spacing follows the general interval commonly seen on EPA-registered rodenticide bait station labels for commensal rodents -- roughly 15-30 ft between stations, tightened toward the 15 ft end for heavier, confirmed infestations and widened toward 30 ft for preventive monitoring where activity hasn't been confirmed. Across their full declared ranges, Building Perimeter (50-5,000 ft) and Interior Square Footage (0-100,000 sq ft) are the inputs that move Exterior Stations and Interior Stations the most, respectively, simply because those ranges span a much wider building-size spectrum than Infestation Level's three-tier spacing adjustment covers -- a small outbuilding and a large commercial facility need very different station counts regardless of infestation severity.
Infestation Level still meaningfully tightens spacing and increases interior placement density for a GIVEN building size, and it also drives the per-station bait load in Initial Bait Needed, since active, confirmed infestations need more bait at first placement than a preventive monitoring setup. This calculator gives a general placement-planning estimate, not a substitute for the specific EPA-registered product label you're using -- always follow the exact spacing, placement, and rate directions on that product's label, which is the legally binding requirement, and confirm state or local restrictions before treating for rodents.
Inputs
Results
Exterior Stations
14
Total Stations
24
How to Use This Calculator
- Measure the Building Perimeter (linear feet around the exterior) and estimate Interior Square Footage needing indoor stations.
- Select the Infestation Level that matches what you've observed: Low (preventive/no signs), Moderate (active signs), or Heavy (confirmed sightings).
- Review Exterior Stations and Total Stations to plan your placement layout.
- Use Interior Stations and Initial Bait Needed (lbs) to budget bait and equipment for the first service.
- Always place bait per the specific EPA-registered product's label directions — this estimate is a general planning guide, not a substitute for that label.
How the result changes with Building Perimeter
| Building Perimeter | Exterior Stations | Total Stations |
|---|---|---|
| 200 | 7 | 17 |
| 300 | 10 | 20 |
| 600 | 20 | 30 |
| 1,000 | 34 | 44 |
What each input means
- Building Perimeter
- Total exterior perimeter of the building in linear feet.
- Interior Square Footage
- Total interior square footage for indoor stations.
- Infestation Level
- Higher infestation levels require closer station spacing and more bait.
What each result means
- Exterior Stations
- Stations placed along the building perimeter.
- Interior Stations
- Stations placed inside the structure.
- Total Stations
- Combined exterior and interior stations.
- Initial Bait Needed
- Total bait weight for initial station loading.
How this is calculated
Worked example, using the default values
- Identify Input Parameters3 parametersBuilding Perimeter = 400, Interior Square Footage = 5000, Infestation Level = 1 = 3 input(s) provided
- Calculate Exterior StationsExterior Stations14 = 14
- Calculate Total StationsTotal Stations24 = 24
- Calculate Interior StationsInterior Stations10 = 10
Engine last updated . Checked against 3 independently-derived tests — how we verify calculators. Built by Paul Gunder, a software engineer, not a licensed financial, medical, or legal professional.
Frequently Asked Questions
What determines station count more: building size or infestation severity?
Across their full ranges, Building Perimeter and Interior Square Footage move the station counts more, simply because a calculator that has to cover everything from a small shed to a large commercial building spans a much wider size range than the three infestation tiers do. For any GIVEN building, though, Infestation Level still meaningfully tightens spacing and raises interior placement density -- both matter, but building size sets the broader scale.
Where does the 15-30 ft exterior spacing figure come from?
It reflects the general interval commonly found on EPA-registered rodenticide bait station product labels for rats -- roughly 15 to 30 feet between placements, with mice typically needing tighter spacing (roughly 8-12 ft). The specific number on any individual product's label is legally binding for that product, so always follow the actual label directions rather than this general estimate when placing bait.
Why does a heavier infestation need more bait per station, not just more stations?
This calculator increases both the station count (via tighter spacing and denser interior placement) and the initial bait load per station as Infestation Level rises, since an active, confirmed infestation typically requires more bait consumed and replenished at each location than a preventive/monitoring-only setup.
Does Interior Square Footage affect Exterior Stations?
No -- Exterior Stations is calculated purely from Building Perimeter and the spacing interval set by Infestation Level. Interior Square Footage only feeds into Interior Stations, which is calculated separately using an interior placement density that also depends on Infestation Level.
What doesn't this calculator account for?
It doesn't account for the specific product's actual EPA-registered label (which is the legally controlling document for spacing, placement, and application rate), building layout and rodent runway locations, non-target species exclusion requirements, or state and local pesticide regulations -- always follow the exact label directions for the product you're using and consult a licensed pest control professional for an active infestation.
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