A dilution ratio tells you how much product to mix with water: 1:8 means 1 part product to 8 parts water. Add the two numbers together, divide the bottle size by that total, and the answer is the amount of product. A CarPro Dilute Spray Bottle has the ratios printed on it, and AutoBead All Purpose Cleaner lists 5:1 to 30:1 for exterior jobs.
How do you work out a dilution ratio?
Add the two numbers in the ratio together, divide your bottle size by that total, and the answer is the amount of product. The rest of the bottle is water. At 1:8 in a 1 litre bottle, 1 + 8 = 9 parts, so you use 111ml of product and 889ml of water.
Dilution Calculator
Choose the ratio on the label and the size of your bottle. The answer fills the bottle exactly.
Ratio on the label (product : water)
Bottle size
- Pour 111ml of product into the bottle.
- Add 889ml of water, which fills it to 1 litre.
- Give it a shake to mix.
1 + 8 = 9 parts. 1,000ml divided by 9 is 111ml of product; the other 889ml is water.
A label that says 10:1 means the same mix as 1:10: the small number is always the product. Always use the ratio on the label. Rather skip the maths? See the bottles with the ratios marked on them.
What does a ratio like 1:8 mean?
A ratio tells you how many parts of water go with each part of product. 1:8 means 1 part product to 8 parts water, so the finished mix is 9 parts in total and only one of them is the concentrate.
You will also see ratios written the other way round, such as 10:1 or 100:1. AutoBead, for example, writes its All Purpose Cleaner ratios as 5:1 to 30:1. In car care the small number is almost always the product and the big number the water, so 10:1 and 1:10 both mean 1 part product to 10 parts water. If a label is unclear, ask the maker or ask us before you mix.
How do you dilute a product step by step?
Here is the method for a pre-wash with a label ratio of 1:8 in a 1 litre bottle. The same steps work for any ratio and any bottle size.
- Add the ratio numbers: for 1:8, 1 + 8 = 9, so the mix is 9 parts in total.
- Check the bottle size: a 1 litre bottle holds 1000ml, so the sums use 1000.
- Work out the product: divide the bottle size by the total parts, so 1000ml divided by 9 is about 111ml of concentrate.
- Work out the water: take the product away from the bottle size, so 1000ml minus 111ml is 889ml of water.
- Mix and label: add the water first, then the product, shake gently and write the product name and ratio on the bottle.
Adding the water first is the method CarPro gives for its Dilute bottle, because some products foam when water is poured onto them, which makes the reading less precise.
Dilution ratio chart
Product first, then water, for the bottle sizes most people use. Figures are rounded to the nearest millilitre.
| Ratio | Total parts | 500ml bottle | 1 litre bottle | 5 litres |
|---|---|---|---|---|
| 1:1 | 2 parts | 250ml + 250ml | 500ml + 500ml | 2500ml + 2500ml |
| 1:2 | 3 parts | 167ml + 333ml | 333ml + 667ml | 1667ml + 3333ml |
| 1:4 | 5 parts | 100ml + 400ml | 200ml + 800ml | 1000ml + 4000ml |
| 1:5 | 6 parts | 83ml + 417ml | 167ml + 833ml | 833ml + 4167ml |
| 1:8 | 9 parts | 56ml + 444ml | 111ml + 889ml | 556ml + 4444ml |
| 1:10 | 11 parts | 45ml + 455ml | 91ml + 909ml | 455ml + 4545ml |
| 1:20 | 21 parts | 24ml + 476ml | 48ml + 952ml | 238ml + 4762ml |
| 1:30 | 31 parts | 16ml + 484ml | 32ml + 968ml | 161ml + 4839ml |
| 1:50 | 51 parts | 10ml + 490ml | 20ml + 980ml | 98ml + 4902ml |
| 1:100 | 101 parts | 5ml + 495ml | 10ml + 990ml | 50ml + 4950ml |
How do you dilute AutoBead All Purpose Cleaner?
AutoBead gives three exterior strengths for its All Purpose Cleaner, written water first, and two for interior use. In a 1 litre spray bottle the exterior strengths work out like this.
- 5:1 for heavy soiling: 1000 divided by 6 is about 167ml of product and 833ml of water.
- 10:1 for medium soiling: 1000 divided by 11 is about 91ml of product and 909ml of water.
- Up to 30:1 for light soiling: 1000 divided by 31 is about 32ml of product and 968ml of water.
Inside the car, AutoBead uses 10:1 for heavy soiling and up to 30:1 for general cleaning. AutoBead also warns that the cleaner may strip exterior wax and sealant protection if used undiluted, and that it is not suitable for leather, which is why the ratio matters.
Which products make dilution easier?
These concentrates give clear ratios on their own labels, the CarPro bottle has the ratios printed on it, and the DTLR sprayer applies the mix. The details come from each maker's own instructions or the product's listing.
A concentrated cleaner for interior plastics, carpet, upholstery, engine bays, door shuts, wheel arch linings and tyre rubber, diluted 5:1 to 30:1 outside and 10:1 to 30:1 inside.
AutoBead Heavy Dirt Citrus Pre Wash
AutoBead dilutes it 10:1 for heavy soiling and 25:1 for everyday use, or 1 part product to 4 parts water in a snow foam lance bottle, and says it is wax and sealant safe at the correct ratio.
AutoBead Alloy Cleaner Concentrate
A wheel cleaner concentrate that AutoBead dilutes at 10:1 for lightly soiled wheels and 2:1 for heavy soiling.
AutoBead adds 7ml to 10ml to a 15 litre bucket of warm water, so a 500ml bottle covers more than 50 washes.
Mosschem Citrus Wash Pre Wash Cleaner
A concentrated citrus pre-wash with recommended dilutions of 100:1, 50:1, 30:1 and 10:1, for a trigger spray, pump sprayer or foam sprayer.
CarPro Dilute Spray Bottle 1 Litre
A bottle with printed ratio markings from 1:1 to 1:30, a space on the label for the product name and ratio, and a CarPro chemical resistant spray head.
A 2 litre pump action pressure sprayer with chemical-resistant Viton seals and an adjustable nozzle, for diluted pre-washes, APCs, citrus cleaners and wheel cleaners.
£21.95In stock
Does using more product clean better?
No. A stronger mix than the label gives costs more, can leave residue to remove and, with some products, can harm protection or surfaces. AutoBead's warning that its All Purpose Cleaner may strip wax and sealant if used undiluted is a good example.
Wheel cleaners and pre-washes that are not pH neutral need the most care. Use the strength the maker gives for the job, start at the weaker end for light dirt, and only move stronger when the label allows it.
Should you stick to the manufacturer's dilution ratio?
Yes. The maker's ratio balances cleaning power, surface safety and value, and it is the strength the product is made to work at. Most labels give a range, so choose the weaker end for light dirt and the stronger end for heavy soiling.
Common questions
Is 1:10 stronger than 1:20?
Yes. 1:10 has 1 part product in every 11 parts of mix, while 1:20 has 1 part in every 21, so 1:10 is roughly twice as strong.
How much is one part water?
One part is whatever measure you use, as long as the product is measured the same way. At 1:4 in a 1 litre bottle there are 5 parts in total, so one part is 200ml: 200ml of product and 4 parts, or 800ml, of water.
What does 1 part water mean?
It means one measure of water for every measure of product stated in the ratio. At 1:1 you mix equal amounts, so a 500ml bottle takes 250ml of product and 250ml of water.
What do two, three or four parts water mean?
Each number tells you how many measures of water go with 1 part of product, and that is the whole meaning: 2 parts water is a 1:2 mix, 3 parts water is 1:3 and 4 parts water is 1:4. So 1 part to 4 parts means 100ml of product and 400ml of water in a 500ml bottle, and 1 part water to 1 part product is an even 1:1 mix.
What is a panel impact ratio?
It is the strength of the mix that actually reaches the paint after a foam lance has mixed the bottle with water from the pressure washer. It is weaker than the mix in the bottle, and how much weaker depends on the lance setting and the machine.
Can I mix two products in one bottle?
Only if both makers say they can be mixed. Otherwise use separate, labelled bottles, and never put a chemical into an unlabelled bottle.
Need help choosing?
Tell the TDHQ team which product you are mixing and what you are cleaning, and we will give you the right ratio. You can also browse our empty detailing bottles, the AutoBead range, every citrus pre-wash and our snow foam lances. For more detail, read our guides to the best citrus pre-wash, the best snow foam and how to wash your car safely.
Last updated 14 October 2026.
