Active Ingredient PPM Converter

This is a four-way pesticide concentration converter: AI % ⇄ finished % ⇄ oz/gal ⇄ ppm. Pick the unit you have; the other three are computed. Every ppm figure carries its basis tag — finished solution or active ingredient — because the two differ by the product's AI fraction and confusing them is the most common mix error.

ppm          = finished% × 10,000          (1 ppm = 0.0001%)
finished%    = ppm ÷ 10,000
oz/gal       = (finished% ÷ AI%) × 1.28 × 128   (AI-aware)
finished a.i. ppm = finished% × (AI% ÷ 100) × 10,000
mL/L         = oz/gal × 7.81                (metric concentrate row)

The basis: a finished-solution ppm counts the whole mix; an active-ingredient ppm counts only the a.i. A 0.06% finished mix of a 9.1%-AI product is 600 ppm finished but 54.6 ppm active ingredient (600 × 0.091). ppm and percent are mass ratios, so they read the same in US and metric; only the per-gallon concentrate row switches between fl oz/gal (auto-stepped to tbsp/tsp for small doses) and mL/L.

The "derived" row: the oz-per-100-gallons ↔ ppm anchor (the ~75 factor) is shown only behind a "derived, verify" label. Its named source was unreachable when this tool was built, so it stands on the unit arithmetic alone (28,350 mg in 100 gallons ≈ 75 ppm) and is never presented as a cited conversion. For liquid SC products at 4–10% AI, route ppm through the AI % (the cited legs), not the raw 75 factor.

Sources: the 1 ppm = 0.0001% identity and the % × 1.28 rule come from OnlinePestControlCourses; the AI-% percent-solution method from PesticideStewardship. The 3.785 L/gal and gallon = 128 fl oz figures are common-knowledge unit constants.