Most chemical labels give a dilution as a ratio such as 1:32 or 32:1. The label does not tell you how many millilitres that is for your 11 litre pump-up sprayer, your 20 litre bucket or your 1 litre trigger bottle. This page does.
Quick answer: A ratio of 1:32 (or 32:1) means 1 part concentrate plus 32 parts water, 33 parts in total. For an 11 litre pump-up sprayer, add 333 mL of concentrate and fill with water to the 11 litre mark. That works out to about 30 mL of concentrate per litre of finished solution.
How to read a dilution ratio
A ratio written as 1:32 or 32:1 on a cleaning chemical label almost always means one part concentrate to 32 parts water. The finished solution is 33 parts. To find the concentrate for any container, divide the container volume by 33.
Labels use four different conventions, and they do not give the same answer:
- 1:X or X:1 (parts of water): 1 part concentrate + X parts water. 1:32 → 1,000 mL ÷ 33 = 30 mL per litre.
- 1 in X (total parts): 1 part concentrate in X parts of finished solution. 1 in 32 → 1,000 mL ÷ 32 = 31 mL per litre. Close to 1:32 for weak dilutions, but at 1 in 4 versus 1:4 the difference is 250 mL against 200 mL per litre.
- Percentage: 2% means 20 mL per litre of finished solution. This is not the same as 1:50 (19.6 mL) and definitely not the same as 1:2.
- mL per litre: The clearest convention. Add that many millilitres to each litre of finished solution.
If a label is ambiguous, use the data sheet, and when in doubt treat 1:X as parts of water: the result is slightly weaker than the alternative reading, which is the safer error.
Dilution calculator for pump-up sprayers, buckets and bottles
Enter your container size and what the label says. The result is how much concentrate to add, then fill with water to the final volume.
The finished solution volume, e.g. 11 for an 11 L pump-up sprayer.
1:32 means 1 part concentrate + 32 parts water.
For 1:32 or 32:1, enter 32.
Cost per RTU litre (optional)
The pack you buy, e.g. 5 for a 5 L drum.
Enter it inc or ex GST; the result will be the same basis.
Add concentrate
333 mL
Then fill with water to
11 L
Per litre of finished solution
30 mL/L
Concentrate cost per litre
$0.00
Cost per RTU litre
$0.00
Cost of this batch
$0.00
Calculation: 11 L × 1,000 ÷ (32 + 1) = 333 mL concentrate; about 10.67 L of water.
Dilution chart: millilitres of concentrate per litre
This chart converts common label ratios into millilitres of concentrate for one litre of finished solution, then for the most common container sizes used in the trade. Figures are rounded to the nearest 5 mL for containers over 1 litre. Measure the concentrate, then fill with water to the stated total.
| Label ratio | Per 1 L | 5 L | 8 L | 11 L | 15 L | 20 L |
|---|---|---|---|---|---|---|
| 1:4 | 200 | 1,000 | 1,600 | 2,200 | 3,000 | 4,000 |
| 1:5 | 167 | 835 | 1,335 | 1,835 | 2,500 | 3,335 |
| 1:8 | 111 | 555 | 890 | 1,220 | 1,665 | 2,220 |
| 1:10 | 91 | 455 | 725 | 1,000 | 1,365 | 1,820 |
| 1:16 | 59 | 295 | 470 | 645 | 880 | 1,175 |
| 1:20 | 48 | 240 | 380 | 525 | 715 | 950 |
| 1:25 | 38 | 190 | 310 | 425 | 575 | 770 |
| 1:32 | 30 | 150 | 240 | 335 | 455 | 605 |
| 1:40 | 24 | 120 | 195 | 270 | 365 | 490 |
| 1:50 | 20 | 100 | 155 | 215 | 295 | 390 |
| 1:64 | 15 | 75 | 125 | 170 | 230 | 310 |
| 1:100 | 10 | 50 | 80 | 110 | 150 | 200 |
| 1:128 | 8 | 40 | 60 | 85 | 115 | 155 |
| 1:200 | 5 | 25 | 40 | 55 | 75 | 100 |
Totals are the finished solution volume, not the amount of water. If your container is a different size, use the calculator above or multiply the "per 1 L" figure by your container's litres.
Worked examples
- 11 L pump-up sprayer, label says 32:1. 11,000 ÷ 33 = 333 mL. Put 333 mL of concentrate in the tank, fill with water to 11 L, close and shake or agitate before pressurising.
- 20 L bucket, label says 1:10. 20,000 ÷ 11 = 1,820 mL. Add 1.8 L of concentrate, then water to 20 L.
- 1 L trigger bottle, label says 1:4. 1,000 ÷ 5 = 200 mL of concentrate, then water to 1 L.
- 5 L container, label says 2%. 5,000 × 0.02 = 100 mL of concentrate, then water to 5 L.
What does a litre of ready-to-use solution cost?
Concentrate price tells you very little until you divide it by the dilution. The number that matters is the cost per ready-to-use (RTU) litre: price per litre of concentrate × the concentrate fraction in the finished mix. At 1:32 that fraction is 1 ÷ 33.
Example: a 5 L drum at $89 is $17.80 per litre of concentrate. Used at 1:32 it costs $17.80 ÷ 33 = 54 cents per RTU litre, so an 11 L pump-up sprayer costs about $5.93 to fill. A cheaper drum at $65 but labelled 1:16 costs $13.00 ÷ 17 = 76 cents per RTU litre, so the dearer product is the cheaper one to use. Enter your pack size and price in the calculator above to compare products on the same basis.
Mixing it correctly
- Measure the concentrate, not the water. Add the measured concentrate first, then fill to the final volume. Adding a full container of water and then the concentrate gives a weaker mix and overfills the tank.
- Use a graduated measuring jug rather than the chemical's cap or a guess. A 10% error on a 1:32 prespray is barely visible; on a 1:4 stripper or an acidic tile cleaner it changes the result and the risk.
- Follow the label on mixing order and water temperature. Most concentrates go into water, not the other way around, and some presprays activate better in warm water. Never mix different products in the same container unless the manufacturer says so.
- Label the sprayer with the product and ratio. An unlabelled tank of "something" is a safety problem and a callback waiting to happen.
- Rinse the sprayer when changing products. Residue from an alkaline prespray can neutralise an acid rinse, and vice versa.
Common mistakes
- Reading 32:1 as 32 mL per litre. It is 30 mL per litre of finished solution (1,000 ÷ 33). Close enough for a prespray, but the same habit applied to 4:1 gives 4 mL instead of 200 mL.
- Treating a percentage as a ratio. 2% is 20 mL/L, which is roughly 1:50, not 1:2.
- Diluting a ready-to-use product. If the label says RTU, there is no ratio to apply.
- Mixing a Hydro-Force bottle at the label ratio. The injector dilutes it again on the way out, so the bottle needs to be stronger. See the Hydro-Force dilution guide.
Dilution questions
Is 1:32 the same as 32:1?
On cleaning chemical labels, yes. Both mean one part concentrate to 32 parts water. The order of the numbers is a labelling habit, not a different dilution.
How many mL per litre is 1:32?
About 30 mL of concentrate per litre of finished solution (1,000 ÷ 33 = 30.3). If the label means "1 in 32 total", it is 31 mL. In practice the difference does not matter.
How much chemical goes in an 11 litre pump-up sprayer at 32:1?
333 mL of concentrate, then water to the 11 litre mark.
How do I convert a percentage to a ratio?
Divide 100 by the percentage and subtract 1 for the water parts: 2% → 100 ÷ 2 = 50 → 1:49, usually quoted as 1:50. Or just multiply the percentage by 10 to get mL per litre: 2% = 20 mL/L.
Can I make a stronger mix for heavy soiling?
Only within the range the label gives. Most presprays list a range such as 1:16 to 1:32. Going stronger than the label's strongest ratio wastes chemical, risks residue and may void product guarantees.
Sprayers, measuring jugs and chemicals
CCW stocks pump-up sprayers, battery sprayers, trigger sprayers and measuring jugs and containers, plus the full range of carpet presprays, spotters and professional cleaning chemicals. Every product page lists the manufacturer's dilution and data sheet.
Dilution figures on this page are arithmetic from the label ratio. Always follow the current product label and safety data sheet for the chemical you are using.
