Fold Dilution Calculator
Pesticides and nutrients are labelled by fold. 1:1000 means 1 mL of stock per litre of water, so a 20 L sprayer takes 20 mL.
Your numbers
Stock (mL)
20mL
Per litre
1mL
Formula
Stock (mL) = Batch size (L) × 1000 ÷ Dilution factor
A larger fold means less stock — 1:500 is twice as strong as 1:1000, not half.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Dilution factor (×)How many times the concentrate was expanded — 1 part to how many. | 1,000 | 1 and up |
| Batch size (L)How much finished liquid you want, in litres. | 20 | 0.01 and up |
Step by step
Quick reference table
Results when only Dilution factor (×) changes and everything else stays put.
| Dilution factor (×) | Stock (mL) (mL) | Per litre (mL) |
|---|---|---|
| 500 | 40 | 2 |
| 750 | 26.67 | 1.33 |
| 1,000 | 20 | 1 |
| 1,500 | 13.33 | 0.67 |
| 2,000 | 10 | 0.5 |
What each result means
| Result | At default values |
|---|---|
| Stock (mL) (mL)How much undiluted concentrate you start with. | 20 |
| Per litre (mL)Concentrate to add for every litre of water. | 1 |
Common mistakes
A larger fold means less stock — 1:500 is twice as strong as 1:1000, not half.
Glossary
- Dilution factor
- How many times the concentrate was expanded — 1 part to how many.
- Batch size (L)
- How much finished liquid you want, in litres.
- Stock (mL)
- How much undiluted concentrate you start with.
- Per litre
- Concentrate to add for every litre of water.
Frequently asked questions
Q. How is Fold Dilution Calculator calculated?
Stock (mL) = Batch size (L) × 1000 ÷ Dilution factor — Pesticides and nutrients are labelled by fold. 1:1000 means 1 mL of stock per litre of water, so a 20 L sprayer takes 20 mL.
Q. Can you walk through an example?
With Dilution factor 1,000×, Batch size (L) 20, the answer is Stock (mL) 20mL.
Q. What do I need to enter?
Enter Dilution factor, Batch size (L). The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Dilution factor (×) moves the answer to Dilution factor (×) 500 → Stock (mL) (mL) 40 and Dilution factor (×) 2,000 → Stock (mL) (mL) 10. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
A larger fold means less stock — 1:500 is twice as strong as 1:1000, not half.
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