Mosquito Larvicide Dosage Calculator

Mosquito dunks are dosed by water surface area, not volume — depth is irrelevant. The surface area drives a single count.

area (sq ft):
  rectangle  = length × width
  circle     = π × (diameter / 2)²
  direct     = entered surface area

dunks per site:
  area ≤ 5 sq ft        → ¼ dunk      (discrete label breakpoint)
  5 < area ≤ 25 sq ft   → ½ dunk
  25 < area ≤ 100 sq ft → 1 dunk
  area > 100 sq ft      → ceil(area / 100)   (1 dunk / 100 sq ft)

total dunks  = dunks per site × number of sites

season supply (optional):
  replacements = ceil(season days / 30)      (replace every ~30 days)
  season dunks = total dunks × replacements

Bits granular equivalent (advisory — re-verify):
  tbsp = ceil(area / 75)

Below 100 sq ft the dose is a discrete breakpoint lookup, not the ÷100 rule — a 3 sq ft birdbath takes ¼ dunk, not a wasteful whole one. Above 100 sq ft it is the headline rate, rounded up so the whole surface is covered. One dunk is roughly a 10 ft × 10 ft patch — about a parking space.

The 30-day cadence is a supply count, not a scheduled appointment — replace a dunk sooner if it has dissolved away or after heavy rain.

The Bits granular rate (1 tbsp / 75 sq ft) and the 4× high-organic-water note are flagged advisories: their label PDFs were not machine-readable at build time, so re-verify them against the EPA-registered label before relying on them. We do not encode the unverified large-area Bits figures.

Sources: Summit Responsible Solutions — Mosquito Dunks (headline rate, fractional guidance, 30-day cadence, Bti active ingredient); IERE — How to Use Mosquito Dunks (duration, reapply after rain); EPA Mosquito Dunks label PPLS 006218-00087 (fractional breakpoint table).

Larviciding standing water is one half of a mosquito program; knocking down adults is the other, and that half runs through equipment you have to calibrate, which the calibrating a thin-fog machine handles from flow rate and swath. Dunks are also a residential pesticide application like any other, so the label's re-entry interval still decides when the yard reopens. When the season plan is set, the mosquito and tick treatment pricing calculator turns the visit count into what to charge per yard.