🧺 Detergent Dosage Calculator

Base dose (g) = Laundry weight (kg) × 10g — a commonly cited approximation for regular soil level. Multiply by a water-hardness factor: soft ×0.8, medium ×1.0, hard ×1.3. For example, 3kg of laundry with medium-hardness water gives 3 × 10 × 1.0 = 30g. Liquid detergent has a density close to water, so 1g ≈ 1mL is a reasonable approximation.

Hard water contains more calcium and magnesium, which react with detergent surfactants and reduce cleaning power (this is also why hard water leaves more soap residue). The same load therefore needs more detergent in hard-water areas to get the same cleaning result. Soft water has fewer minerals, so detergent works more efficiently and less is needed.