Laundry detergent dosage calculator
How much liquid detergent a load really needs — over-dosing wastes money and leaves residue, under-dosing leaves it dirty. It scales a base dose by load size, how soiled the wash is, water hardness and whether the machine is high-efficiency, and gives millilitres and cap-fulls.
Related tools
All Practical tools →The Laundry detergent dosage calculator turns Load size, Soil level, Water hardness, Machine type into Detergent (ml), Cap-fulls (≈35 ml each), instantly and for free. For instance, with Load size = Small (¼ full), Soil level = Lightly soiled, Water hardness = Soft and Machine type = High-efficiency (HE) it returns Detergent (ml) = 15.984 and Cap-fulls (≈35 ml each) = 0.457.
How to use it
- Enter your values: Load size, Soil level, Water hardness, Machine type.
- Read the result instantly: Detergent (ml), Cap-fulls (≈35 ml each).
Frequently asked questions
What does the Laundry detergent dosage calculator actually compute?
It takes Load size, Soil level, Water hardness and Machine type and derives Detergent (ml) and Cap-fulls (≈35 ml each) from them. The calculation is live as you type, so the result updates on every change.
What information do I need to provide?
4 values: Load size, Soil level, Water hardness and Machine type. Nothing else is required — no account, no file upload.
Can you show a worked example?
With Load size = Small (¼ full), Soil level = Lightly soiled, Water hardness = Soft and Machine type = High-efficiency (HE), the calculator returns Detergent (ml) = 15.984 and Cap-fulls (≈35 ml each) = 0.457. Those figures come from running this exact tool, so you can reproduce them by entering the same values.
What happens if I enter larger values?
It moves a lot. Using Load size = Medium (½ full), Soil level = Normally soiled, Water hardness = Medium and Machine type = Standard (top-load) instead, Detergent (ml) goes from 15.984 to 55.5 — which is why it is worth testing a few scenarios rather than trusting a single figure.
Which “Load size” option should I choose?
You can pick between « Small (¼ full) », « Medium (½ full) », « Large (¾ full) » and « Extra large (full) ». Each one changes what the calculator works out, so switch and compare — the default is « Small (¼ full) ».
When would I actually use this?
The questions no reference answers: what a meeting is costing while it runs, how many hours a commute has taken out of a year, how much detergent a load actually needs, and a few that exist for the pleasure of knowing — how many popcorn kernels would fill a room, what a hamster generates.
What is the most common mistake?
Quoting the playful ones as if they were measurements. A room filled with popcorn and a salary counted in bathroom breaks are arithmetic done honestly on premises chosen for fun; the number that comes out is exactly as solid as the assumption you fed it, which is the joke.
How accurate is it, and what are the limits?
A guideline — always follow the dose on your detergent's label.
What is the difference between the Laundry detergent dosage calculator and the Fishing knot strength calculator?
This one returns Detergent (ml) and Cap-fulls (≈35 ml each); the Fishing knot strength calculator returns Knot efficiency and Breaking strength (lb). That is the whole difference — open the one whose figure you need.
Is there a tool for the next step?
Popcorn fill room calculator is the closest one after this: A gloriously pointless question, answered with real physics: how many pieces of popcorn would it take to fill a room? From the dimensions and a kernel type it accounts for the air gaps between pieces (~64% packing) and returns the count, weight, cost and a few absurd comparisons.