What this calculator does
Many products are mixed by ratio: cleaning concentrate, plant food, paint, two-part epoxy, mortar. The label says something like "1 : 4", and you still need to know how many cups or ounces that means for your bucket. This tool does the arithmetic.
How to use it
- Enter the two parts of the ratio, such as 1 and 4.
- Then type either the total you want to make or the amount of ingredient 1 you already have.
- Press Work it out.
The method
Starting from ingredient 1 instead? If you have 100 of it, one part is 100 ÷ 1 = 100, so ingredient 2 is 4 × 100 = 400 and the total is 500.
Examples you can try
| Ratio | You know | Amounts |
|---|---|---|
| 1 : 4 | Total 500 | 100 and 400 |
| 1 : 9 | Total 1,000 | 100 and 900 |
| 2 : 1 | 6 of ingredient 1 | 6 and 3 (total 9) |
| 1 : 50 | Total 128 | 2.51 and 125.49 |
Where people use it
- Cleaning and garden: diluting concentrates and fertilizer.
- Painting and building: tinting, thinning and mortar mixes.
- Hobbies: resin, epoxy and small-engine fuel.
Safety tips
- Always follow the product label first. This tool only does the math.
- Say clearly whether the ratio is by volume or by weight, and use the same unit for both ingredients.
- Check whether the label ratio means "parts of concentrate to parts of water" or "total parts". A 1 : 4 mix is 5 parts in all.
Read our short guide with worked examples you can follow on paper.
Frequently asked questions
How do I calculate a mixing ratio?
Add the ratio parts, divide your total by that sum to get one part, then multiply each ingredient's parts by it.
What does a 1:4 mix mean?
One part of the first ingredient to four parts of the second, which is five parts in all.
Is 1:4 the same as 1 part in 4?
No. 1 : 4 is five parts in total (one plus four). "1 part in 4" usually means one of four total parts. Check the label wording.
Can I use any unit?
Yes. Use the same unit for both ingredients, such as ounces, cups or milliliters.
How much oil do I need for 50:1 fuel in 1 gallon?
A gallon is 128 fluid ounces, so one part is 128 ÷ 51, which is about 2.5 oz of oil. Check your engine manual for the exact mix.