Detergent Dosing Calculator
Enter your load weight, water hardness, soil level, and detergent concentration for a starting-point dose in milliliters and tablespoons.
Recommended dose
The dose is a moving target, not a fixed capful
A detergent bottle can only print one dosing guideline, calibrated for an "average" load at "average" water hardness. Your actual laundry rarely matches that average exactly — a half-full drum of lightly worn clothes needs far less than a full load of muddy sports kit, and a home on hard well water needs meaningfully more than one on naturally soft water to get the same result.
This calculator scales a base rate of roughly 15ml of standard liquid detergent per kilogram of dry laundry by those three factors, giving you a more tailored starting point than a single bottle-cap line ever can.
Frequently Asked Questions
Does using more detergent get clothes cleaner?
No — past a certain point, extra detergent doesn't clean better, it just leaves more residue behind. Detergent that isn't fully rinsed out can leave clothes feeling stiff, dull colors, and even irritate sensitive skin. Bottle-cap markings and dosing scoops are calibrated for an average load, which is exactly why adjusting for your actual load weight, water hardness, and soil level gets you closer to the right amount than guessing a capful every time.
Why does hard water need more detergent?
Hard water carries dissolved calcium and magnesium that react with surfactants before they ever reach your clothes, effectively using up some of the detergent's cleaning power on the water itself rather than the fabric. The harder the water, the more of a standard dose gets consumed this way, which is why hard-water regions typically need a noticeably higher dose — or a water softener — to get the same cleaning result as a soft-water area.
What's the difference between concentrated and ultra-concentrated detergent?
It's simply how much active cleaning ingredient is packed into each milliliter or gram. A standard detergent might need a full cap per load, a concentrated formula does the same job in about half that volume, and an ultra-concentrated formula in roughly a third — so always check the dose printed on your specific bottle rather than assuming every 'concentrated' label means exactly the same multiplier.
Starting point only. Detergent formulations vary — always check the dose printed on your specific product's label.