Včelkulačka is a free calculator from Beentry that makes it easier for beekeepers to prepare sugar solutions, treatment mixtures, and evaluate the health of bee colonies. Včelkulačka has become one of the most popular tools among Czech and Slovak beekeepers. In this article, we will show you 5 specific scenarios where it saves you time and mainly helps you avoid dosing mistakes.
What can Včelkulačka do?
Včelkulačka contains 8 specialized calculators for the most common calculations beekeepers need during the season. From preparing sugar solutions to mixing treatment acids to evaluating varroasis — each calculator works with precise ratios and automatically recalculates the required amount of ingredients based on the entered volume.
Scenario 1: Preparing sugar solution for spring stimulation
In spring, you need to stimulate the colonies with a thin sugar solution in a 1:1 ratio (equal parts sugar and water). But how much exactly sugar and water do you need for 10 liters of solution? Most beekeepers estimate this, but an accurate calculation is important — too thin a solution does not interest the bees, too thick is unsuitable for spring stimulation.
In Včelkulačka, you simply set the desired volume and immediately see the exact weight of sugar and volume of water. Additionally, the app alerts you that the solution must not be heated above 60 °C because hydroxymethylfurfural (HMF) forms, which is poisonous to bees.
Scenario 2: Winter feeding with 3:2 solution
In August and September, it is time to supplement winter supplies with a thicker 3:2 solution (3 parts sugar to 2 parts water). Each colony needs roughly 15–20 kg of supplies for winter. Včelkulačka precisely calculates how many kilograms of sugar and liters of water you need for the desired volume — just set the slider.
Scenario 3: Treating varroa with oxalic acid
Oxalic acid drip is one of the most effective methods of treating varroa in the broodless period. But preparing the solution requires precise dosing — you need to know the correct ratio of oxalic acid dihydrate, sugar, and distilled water. A dosing mistake can harm the bees.
Včelkulačka calculates the exact amounts of all three ingredients based on the number of colonies you want to treat. It distinguishes between summer and winter application and alerts you to the correct procedure.
Scenario 4: Diluting formic acid
Formic acid is used to treat varroa in summer when brood is present in the hive. You need to dilute 85% acid to a 65% solution — and this is where mistakes are most common. Včelkulačka calculates the exact volume of 85% acid and water for the desired amount of 65% solution. Remember — always pour acid into water, never the other way around!
Scenario 5: Evaluating varroa from the debris
Regular monitoring of varroa infestation is key to the health of bee colonies. Včelkulačka includes a calculator where you enter the number of bees in the sample and the number of mites found. Based on this, it calculates the infestation percentage and compares it with threshold values for the given month — the limit in July differs from September. The result clearly indicates whether immediate treatment is necessary or the situation is under control.
New: Včelkulačka is also available on the web
From 2026, you can use Včelkulačka directly in your browser at vcelkulacka.cz — no installation, no registration, free. The web version includes all calculators and works on any device with a browser.
For offline use directly at the apiary, where there is often no mobile signal, we recommend downloading the mobile app for iOS or Android. The mobile version works completely offline — simply download it and all calculators are available anytime and anywhere, even without mobile signal.
Download Včelkulačka for free
Včelkulačka is completely free and ad-free. It is part of the Beentry ecosystem — a Czech app for complete bee colony management. Whether you are preparing sugar solution in spring or dealing with varroa treatment in autumn — with Včelkulačka you will always have the correct calculation at hand.
Developer and co-founder of Beentry. He leads the technical development of the app and web tools for beekeepers.