Laundry Detergent Calculator
Detergent dosing guidance depends on your water hardness, and running out mid-week is an easy way to end up using a rushed, incorrect amount. Enter your laundry habits and water hardness below to see how far a bottle really goes.
Work out how far a bottle of detergent goes
Enter your laundry habits and water hardness to see how often you'll need to restock.
Most of the Midlands and North East
At a 50ml dose per wash, a 2000ml bottle gives you:
40 loads
That's about 8.0 weeks per bottle, or around 7 bottles a year at your current wash frequency.
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A few well-reviewed laundry essentials.
£24.99
Pros
- Three tiers fit a full wash load in a small footprint
- Folds flat for easy storage between uses
Cons
- Lightweight steel frame can wobble with heavy wet towels
- Aluminium
- 18kg / 21m Drying Space
£89.99
Pros
- Gently heated bars speed up indoor drying without a tumble dryer
- Much cheaper to run than a tumble dryer for everyday laundry
- 21m of drying space with an 18kg capacity
Cons
- Takes up floor space for the duration of drying
- Polyester
£19.99
Pros
- Folds flat to almost nothing when not in use
- Water-resistant coating with soft handles for wet or dry laundry
Cons
- No lid, so contents are visible in open-plan utility rooms
Frequently asked questions
Why does water hardness affect how much detergent I need?
Hard water contains more dissolved minerals, which react with detergent and reduce how effectively it lathers and cleans, so manufacturers recommend a higher dose in hard water areas to get the same washing results as in soft water areas.
How do I find out if I have hard or soft water?
Most UK water suppliers publish hardness maps or a postcode lookup on their website. As a rough guide, much of the South and East of England has hard water, while Scotland, Wales and the North West tend to have softer water.
Does using less detergent than recommended save money?
Using too little can leave clothes less clean and cause a build-up of residue and odour over time, particularly with hard water, which may mean re-washing loads — often costing more in the long run than dosing correctly to begin with.
Are detergent tablets or pods a better measure than liquid?
Pods and tablets give a fixed, pre-measured dose regardless of water hardness guidance, which is convenient but less flexible — with liquid or powder detergent, you can adjust the dose to your specific water hardness and load size.