How It Works
This calculator works in 4 steps.
Enter the ratio
Type the 2 numbers, such as 1 and 4 for 1:4.
Choose the convention
Select concentrate-to-diluent (parts to parts) or concentrate-to-total (parts of the final mix).
Enter the total volume
Type the volume of finished solution, such as 1 L or 1 US gal (3.785 L).
Read the concentrate and diluent volumes
The calculator divides the total by the number of parts and multiplies by each part count.
The Formula
The formula divides the total volume by the sum of ratio parts and multiplies by each part.
Parts = a + bV_conc = V_total × a / (a + b)V_dil = V_total × b / (a + b)- a:
- Concentrate parts
- b:
- Diluent parts
- V_total:
- Total volume of mix
- V_conc / V_dil:
- Concentrate and diluent volumes
A 1:3 ratio for 1,000 mL makes 4 parts of 250 mL each: 250 mL concentrate and 750 mL water.
Conversion Table
The conversion table splits 7 common parts-to-parts ratios into concentrate and diluent volumes.
| Ratio (conc:dil) | Total parts | Total volume | Concentrate | Diluent |
|---|---|---|---|---|
| 1:1 | 2 | 500 mL | 250 mL | 250 mL |
| 1:3 | 4 | 1,000 mL | 250 mL | 750 mL |
| 1:4 | 5 | 1,000 mL | 200 mL | 800 mL |
| 1:9 | 10 | 500 mL | 50 mL | 450 mL |
| 1:15 | 16 | 1,600 mL | 100 mL | 1,500 mL |
| 1:32 | 33 | 3,785 mL | 114.7 mL | 3,670 mL |
| 1:64 | 65 | 3,785 mL | 58.23 mL | 3,727 mL |
3,785 mL = 1 US gallon. Ratios follow the concentrate-to-diluent convention.
What Is the Dilution Ratio Calculator?
The Dilution Ratio Calculator is a mixing tool that splits a total volume into concentrate and diluent portions according to an explicitly defined ratio, such as 1:4 (1 part concentrate to 4 parts water). The user states which convention the ratio follows before calculating, so the result does not depend on guesswork.
Dilution ratios appear on cleaning product labels, photographic chemistry, horticulture products, and lab protocols. A ratio of 1:4 in the parts-to-parts convention makes 5 total parts, so 1 L (33.8 US fl oz) of mix holds 200 mL of concentrate and 800 mL of water. The calculator outputs volumes in mL, L, US fl oz, and US gallons (gal).
Common Uses
There are 5 main uses of this calculator.
Product label instructions
Users mix cleaning concentrates labeled 1:10, 1:32, or 1:64.
Photographic developers
Darkroom users mix developers such as 1:1 and 1:9 stock-to-water dilutions.
Garden and plant products
Gardeners mix liquid feed concentrates into watering cans.
Lab recipes in parts
Technicians follow recipes written as parts, such as 1 part reagent to 2 parts water.
Batch scaling
Users scale one ratio from a 500 mL spray bottle to a 5 US gal (18.9 L) bucket.