Varroa Mite Treatment Calculator

Calculate infestation percentage, get a treatment recommendation, and verify post-treatment efficacy. Free. No signup. Nothing gets sent anywhere — all math happens in your browser.

Step 1: Calculate mite infestation

Sample roughly 300 bees (about half a cup) from a brood frame. Shake in alcohol or soapy water, count the mites that fall out, and enter both numbers below.

Standard sample size is 300 bees.

Total mites found in the wash.

Economic thresholds (Honey Bee Health Coalition): <1% low · 1–3% moderate · 3–5% high · >5% severe. Treat above 3% during active season; above 1% heading into winter.

Step 2: Verify treatment efficacy

After a treatment ends, wait 2–4 weeks and repeat the count. Enter your pre-treatment and post-treatment mite counts to calculate the efficacy percentage. Target is ≥ 90%.

Efficacy formula: (pre-count − post-count) ÷ pre-count × 100. A well-applied treatment should hit 90%+. Persistent sub-target results usually indicate resistance (common with Apivar, mostly broken in many regions) or application error.

Related reading

Varroa Mite Treatment Guide: When, What & How to Treat

Full guide to oxalic acid, formic acid, Apivar, thymol, and IPM strategy by season.

Track Treatments in HiveSense

Log mite counts, schedule treatments, get reminders for removal dates — all in one app.

New to beekeeping?

Our beekeeping starter kit guide covers protective gear, hive types, and the smart-sensor options that pair with HiveSense.

Keep every mite count on file

HiveSense logs mite counts per hive, calculates efficacy automatically, and reminds you when the next count is due.

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Read the full treatment guide