A can of cleaning agent at a low price per liter can be more expensive to use than a concentrate with a higher price per liter. Compare the recommended dosage for the same task and calculate the price for the solution the employees actually use.
The dosage must always be obtained from the specific product's label or product data sheet. The examples below show the math; they are not dosage instructions for a specific cleaning agent.
Start with the task and the product's instructions
Check that the agent is intended for the surface, the type of dirt and the working method. Then note the dosage unit: ml per liters of water, percentage of finished solution or another indication.
A ready-to-use product and a concentrate must not be treated the same. Also follow instructions on, among other things, temperature, working time and possible rinsing. The Danish Environmental Protection Agency emphasizes that incorrect dosing can leave residues and that more detergent does not in itself give a cleaner result.
How do you calculate ml per liter of water
If the instructions say 5 ml per liters of water, the quantity is calculated as follows:
Milliliters of concentrate = number of liters of water × ml per liters.
| Water amount | Concentrate at 5 ml/l water |
|---|---|
| 1 liter | 5 ml |
| 5 liters | 25 ml |
| 10 liters | 50 ml |
Here the dosage is defined per liters of water. It is not exactly the same definition as a percentage of the finished solution.
How to calculate the percentage
If the manufacturer states 0.5 volume percent of the finished solution, 10 liters of finished solution must contain 50 ml of concentrate. The calculation is 10 × 1,000 × 0.5 ÷ 100 = 50 ml.
Follow the manufacturer's procedure so that the total final volume is 10 liters. If the instructions instead use percentage by weight or a dosage per liters of water, that calculation method must be used. If a mixing ratio is unclear, the supplier must explain it; avoid guessing the meaning of, for example, "1:100".
Calculate the concentrate's price per working solution
Calculating example: A can with 5 liters of concentrate costs DKK 200 excl. VAT The price per ml is 200 ÷ 5,000 = DKK 0.04. At a dosage of 5 ml per liter of water, the concentrate costs DKK 0.20 per liter of water being prepared, or DKK 2 for a portion of 10 liters of water.
That is only the chemical cost. Working time, water, machines and possible finishing are not included. Therefore, only compare products that are suitable for the same task and give the required result at the prescribed dosage.
If in the example 10 ml is poured in instead of 5 ml, the concentrate consumption is doubled. It does not document a doubling of the cleaning effect.
Make correct dosing easy in everyday life
- Use a suitable measuring cup, a dosing pump or a suitable dosing system. Check how much the equipment actually dispenses.
- Write product, work task and indicated quantities in the work instruction so that employees do not have to recalculate during each task.
- Use suitable, clean containers and follow product instructions for labeling and shelf life after dilution.
- Prepare only the amount needed within the allowed storage time.
Do not mix different cleaning agents. The choice of protective equipment when handling the concentrate must follow the workplace's chemical risk assessment and the information in the safety data sheet. See also our guide for choosing gloves when cleaning.
Use the dosage in your next purchase
Ask for dosage instructions, product data sheet, safety data sheet and package size along with the price. Record the actual consumption per place of work, so reorders are based on the use.
See cleaning agents and cleaning articles at Nordic Safety, including universal cleaning without perfume. Always obtain the dosage instructions for the selected product. If you need to clarify use or documentation, you can contact us with the name of the product and work task.
Sources and professional basis
- The Swedish Environmental Agency: dosage and safe use of cleaning agents.
- Kiilto: preparation and storage of solutions for use.
- The Norwegian Occupational Safety and Health Administration: chemical risk assessment and protective agents.
Sources checked 10 October 2026. All prices and dosage figures in the calculation examples are illustrative.
