Skip to content
HobbyHQ
Search

Automotive detailing

Dilution calculator

A stated concentrate ratio applied to the bottle you own, and an explicit answer to the arithmetic slip that makes almost every home-diluted bottle stronger than it should be.

The question this answers: “The label says 1:10 and my bottle is 500ml. Is that 50ml of product, or something else?”

The number after the colon on your label. Enter 10 for 1:10.

Result

Concentrate
45.5 ml
Water
454.5 ml
Working strength
9.09%
Useful for comparing two products quoted in different ways — one as a ratio and one as a percentage.
For 1 bottle
45.5 ml concentrate, 455 ml water
The mistake this avoids
Dividing by 10 instead of 11 gives 50 ml — about 10% too strong
1:10 means one part concentrate to ten parts water, so eleven parts in total. Dividing the bottle by ten is the commonest error in the hobby and it wastes product rather than improving the result.

Worth knowing about this answer

  • Dilution ratios are the manufacturer’s, and they differ between products that look identical. This tool applies the figure you give it and has no view on what the right figure is.
Show the working
  1. Total parts1 + 1011
  2. Concentrate500 ml ÷ 1145.5 ml
  3. Water500 − 45.5454.5 ml

Concentrate: 45.5 ml. Water: 454.5 ml. Working strength: 9.09%. For 1 bottle: 45.5 ml concentrate, 455 ml water. The mistake this avoids: Dividing by 10 instead of 11 gives 50 ml — about 10% too strong

How it works

A ratio of 1:n means one part concentrate to n parts water, so the total is n plus one parts. The concentrate is the bottle divided by that total, and the water is the remainder. The working strength is reported as a percentage so a product quoted as a ratio can be compared with one quoted as a percentage.

What it assumes

  • That the ratio is parts of water to one part concentrate, which is the usual convention on detailing products. A few are quoted as a percentage or as a total-parts figure, and the label is the authority rather than this tool.
  • That the volumes add. For the dilutions used in this hobby the error from assuming that is far smaller than the accuracy of a measuring jug.

Where it stops being reliable

  • It has no view on what dilution to use. That is the manufacturer’s figure, it differs between products that look identical, and it often differs by job for the same product.
  • It says nothing about compatibility, contact time, panel temperature or personal protective equipment, all of which matter more than the arithmetic and all of which are on the product’s own documentation.
  • It is not a cost calculator. What a dilution costs per bottle depends on what you paid for the concentrate.

Runs entirely in your browser — nothing you type is sent anywhere. Last reviewed 2026-08-19. More on Automotive detailing.