By David Thompson | Updated March 24, 2022

For most scientific applications, a 20% (w/v) sugar solution contains 20 g of sugar per 100 mL of water. If you’re unsure of the required ratio or solvent, confirm with the requestor.

Step 1 – Calculate the Sugar Mass

Multiply 0.20 by the total volume (mL) you need. For a 100 mL solution, that’s 100 × 0.20 = 20 g of sugar.

Step 2 – Weigh the Sugar

Use a calibrated balance. Subtract the tare weight of the container or paper used to hold the sugar before recording the final mass.

Step 3 – Transfer to a Graduated Container

Place the weighed sugar in a vessel with milliliter markings.

Step 4 – Dissolve and Complete the Volume

Pour roughly two‑thirds of the total water volume into the container. Stir with a glass rod until the sugar dissolves. Once the mixture is still, add the remaining water to reach the desired volume, then stir again to ensure homogeneity.

Materials Needed

• Analytical balance (accuracy ±0.01 g)
• Graduated cylinder or volumetric flask (clear markings)
• Glass stirring rod or magnetic stirrer

Follow these steps to obtain a precise 20% sugar solution suitable for physiological studies, microbiological media, or culinary applications.