BeeCalc — Beekeeper's Calculator
Mix the right syrup, dilute acids precisely, check your colony's health. All in a few clicks.
Why BeeCalc?
No more digging through notes for formulas. Enter the amount, slide the bar and instantly know what to add. Works offline in the field — and it's free.
Sugar syrups
1:1 syrup for stimulation, 3:2 for winter stores, honey dough for feeding — exact ratios in one click.
Acid dilution
Oxalic, formic, lactic — diluted precisely to be effective and safe for your bees.
Varroa check
Count mites from a wash, evaluate infestation level and know when it's time to treat.
The app facilitates calculations. The beekeeper is always responsible for colony treatment.
Calculate:
Sugar Water 1:1
Sugar water in a 1:1 ratio (sugar:water) is used in spring to stimulate colonies and encourage the queen to lay. Feed in small doses (0.5–1 l) repeatedly over several days. Do not bring to a boil — this produces hydroxymethylfurfural (HMF), which is toxic to bees. Dissolve sugar in warm water (max 60 °C) and stir until fully dissolved.
Sugar Water 1:1
Sugar water in a 1:1 ratio (sugar:water) is used in spring to stimulate colonies and encourage the queen to lay. Feed in small doses (0.5–1 l) repeatedly over several days. Do not bring to a boil — this produces hydroxymethylfurfural (HMF), which is toxic to bees. Dissolve sugar in warm water (max 60 °C) and stir until fully dissolved.
Sugar Water 3:2
A thicker sugar solution in a 3:2 ratio (sugar:water) is used to replenish winter stores. Feed in late summer and autumn when bees need sufficient reserves for overwintering. Do not bring to a boil — this produces hydroxymethylfurfural (HMF), which is toxic to bees. A colony typically needs 15–20 kg of stores for winter, depending on colony strength and region.
Honey Dough 1:3
Honey dough is prepared by mixing honey and powdered sugar in a 1:3 ratio. It is used as emergency feed in winter or early spring when colonies are at risk of starvation. Place the dough directly on top of the frames under the hive lid. Bees regulate their own intake — they consume it gradually as needed.
Oxalic Acid Dribble
Dribbling with oxalic acid solution is one of the most effective methods for treating varroosis during the broodless period. To prepare the solution, use oxalic acid dihydrate (OA), sugar and distilled water — see the calculation below. Treatment should be done once per season — repeated dribbling can harm bees. Apply the solution with a syringe directly onto the bees between frames.
Dilution of Formic Acid
Formic acid at 65% concentration is used to treat varroosis during summer when brood is present. It works on mites on bees and partially on mites in capped brood. The exact dilution ratio of 85% FA to 65% solution is calculated below.
Dilution of Lactic Acid
Lactic acid at 15% concentration is used to treat nucleus colonies and small colonies without capped brood. The exact dilution ratio of 80% lactic acid to 15% solution is calculated below. Apply with a sprayer directly onto the bees frame by frame. Can be repeated at 3–4 day intervals.
OA and Glycerin Solution
A mixture of oxalic acid and glycerine is used to prepare long-lasting carriers — soaked wicks or cloths placed inside the hive. Unlike a one-time dribble, this method works continuously over several weeks.
Mite Wash-off Evaluation
The mite wash is the most accurate method for determining the level of Varroa destructor infestation in a colony. A sample of 200–300 bees is taken from a brood frame (never from the honey super). Shake the bees into a sealable container and cover with alcohol. After shaking, count the fallen mites. The resulting infestation percentage is compared against monthly threshold values.
Frequently Asked Questions
A 1:1 syrup is used in spring to stimulate colonies — fed in small doses depending on the weather, usually March–April. A thicker 3:2 syrup is prepared in late summer (August–September) to replenish winter stores. It is important that each colony has 15–20 kg of stores for winter.
Shake 200–300 bees from a brood frame into a sealable container and cover with alcohol. After shaking thoroughly, count the fallen mites and divide by the number of bees. Compare the result with threshold values for the given month — in July the critical threshold is lower than in September, because in summer there is still time to act before the winter bee generation emerges.
Oxalic acid dribble treatment is performed once per season, ideally during the broodless period (late autumn or winter). Repeated dribbling can harm the bees. For summer treatment when brood is present, formic acid is more suitable.
Hydroxymethylfurfural (HMF) is a substance that forms when sugar is overheated — especially when boiling sugar syrup. It is toxic to bees and damages their digestive system. Therefore, sugar syrup must never be brought to a boil — dissolve sugar in warm water at max. 60 °C.
Oxalic acid applied by standard dribbling only affects mites on the bees and is used during the broodless period (once per season). Formic acid also penetrates capped brood, which is why it is used in summer. Each has different dilution ratios and application methods — the calculator will work out the correct proportions for you.
The web version requires an internet connection. For use at the apiary without a signal, download the BeeCalc mobile app for iOS or Android — it works completely offline and includes all calculations.
