Dilution Ratio Calculator
Enter your dilution ratio and target volume to find exactly how much concentrate and water you need. Switch modes to solve C1V1=C2V2 for any unknown, calculate how much solvent to add to a fixed amount of stock, convert between ratio notation and dilution factor, or generate a full serial dilution series. Results update as you type.
Formula
Worked example
To make 1 litre of working solution from a 1:9 concentrate-to-water product: total parts = 1 + 9 = 10. Concentrate = 1000 mL / 10 = 100 mL. Water = 1000 - 100 = 900 mL. Dilution factor = 10x. Final strength = 10%.
What is a dilution ratio?
A dilution ratio expresses how much concentrate is mixed with how much diluent (usually water) to create a working solution. The notation "1:x" can mean two different things depending on context: "1 part concentrate to x parts water" (common on UK and US cleaning product labels, giving x+1 total parts) or "1 part concentrate in x parts total" (used in some scientific and European contexts, giving a dilution factor of exactly x). This calculator handles both conventions: simply select the one printed on your product or used in your protocol. For example, a 1:9 ratio (to water) means 100 mL concentrate plus 900 mL water gives 1 litre of working solution at 10% strength, while a 1:9 ratio (in total) means 111 mL concentrate plus 889 mL water.
How C1V1 = C2V2 works
The dilution equation C1V1 = C2V2 states that the amount of solute (concentration times volume) is conserved when you dilute a solution. C1 is the starting concentration, V1 is the volume of stock you take, C2 is the target concentration, and V2 is the final total volume. You can solve for any one of the four variables if the other three are known. For example, to prepare 100 mL of a 10% solution from a 100% stock: V1 = (10% x 100 mL) / 100% = 10 mL of stock, topped up to 100 mL with water. This formula works for any concentration unit (%, mol/L, mg/mL) as long as both concentrations use the same unit and both volumes use the same unit.
Dilution factor vs dilution ratio: what is the difference?
The dilution factor is a single number representing how many times more dilute the final solution is compared to the stock. A 1:9 ratio (concentrate to water) gives a dilution factor of 10 because the total volume is 10 times the concentrate volume. A dilution factor of 10 is sometimes written as "10x" or "tenfold dilution." Confusingly, some product labels use "1:10" to mean a dilution factor of 10 (1 part in 10 total) rather than 1 part to 10 parts water (which would be a dilution factor of 11). Always check which convention your product uses. This calculator converts between ratio and factor in the "Ratio to dilution factor" mode.
Serial dilutions explained
A serial dilution is a series of equal-step dilutions where each tube is diluted from the previous one by the same factor. For example, a tenfold serial dilution starting at 1 mg/mL gives 0.1, 0.01, 0.001 mg/mL and so on. The concentration at each step is C0 divided by the factor raised to the power of the step number (Cn = C0 / factor^n). Serial dilutions are essential in microbiology for colony counting, in chemistry for preparing calibration standards, and in pharmacology for dose-response curves. They let you span many orders of magnitude with a small number of steps.
Common dilution ratios and their uses
| Ratio (1:x) | Dilution factor | Final strength | Typical use |
|---|---|---|---|
| 1:1 | 2x | 50% | Hair dye developers, strong disinfectants |
| 1:3 | 4x | 25% | Heavy-duty degreasers, floor strippers |
| 1:9 | 10x | 10% | General-purpose cleaners, bleach solutions |
| 1:19 | 20x | 5% | Light-duty surface sprays, glass cleaners |
| 1:31 | 32x | 3.1% | Concentrated all-purpose cleaners (common label ratio) |
| 1:63 | 64x | 1.6% | Odour neutralisers, fabric fresheners |
| 1:99 | 100x | 1% | Sanitisers, low-concentration disinfectants |
| 1:127 | 128x | 0.78% | Highly concentrated industrial cleaners |
Typical 1:x (concentrate to diluent) ratios for household and professional products.
Frequently asked questions
What does 1:10 dilution mean?
It depends on the convention. In most cleaning product labeling, 1:10 means 1 part concentrate mixed with 10 parts water, giving 11 parts total and a dilution factor of 11. In some scientific contexts, 1:10 means 1 part concentrate in 10 parts total (a dilution factor of exactly 10). This calculator lets you choose which convention applies to your situation. When in doubt, check the product label for the resulting percentage or the recommended volume per litre.
How do I make a 1:32 dilution?
A 1:32 ratio (concentrate to water) means 1 part concentrate to 32 parts water, giving 33 parts total. To make 1 litre: divide 1000 mL by 33 to get about 30.3 mL concentrate, then add 969.7 mL water. The dilution factor is 33 and the final strength is about 3%. If your label uses the "in total" convention, 1:32 means 1 part in 32 total: 1000 / 32 = 31.25 mL concentrate plus 968.75 mL water, dilution factor 32.
How do I use C1V1 = C2V2?
Identify the three known values and the one you want to find. Rearrange: V1 = (C2 x V2) / C1 to find the stock volume; V2 = (C1 x V1) / C2 to find the final volume; C2 = (C1 x V1) / V2 to find the final concentration. For example, to make 500 mL of 5% solution from a 70% stock: V1 = (5 x 500) / 70 = 35.7 mL of stock, topped up to 500 mL. Always use the same units for each pair (C in %, V in mL, etc.).
What is the difference between a 10x and 10-fold dilution?
A 10x or tenfold dilution means the final concentration is one tenth of the original. This corresponds to a dilution factor of 10, which is a 1:9 ratio (1 part stock plus 9 parts diluent = 10 parts total). The terms "10x dilution" and "10-fold dilution" are interchangeable, and both mean dilution factor = 10.
Can I dilute to a higher concentration?
No - dilution only reduces concentration. If you need a higher concentration than your stock, you must either start with a more concentrated stock or evaporate some solvent. The C1V1 = C2V2 formula only applies when C2 is less than or equal to C1. The "Solvent to add" mode will return no result if the target concentration is higher than the stock concentration.
How do I calculate a 1:100 dilution?
A 1:100 ratio (concentrate to water) means 1 part concentrate to 100 parts water, totalling 101 parts, with a dilution factor of 101 and a final strength of about 0.99%. For "in total" convention, 1:100 means 1 part in 100 total: dilution factor exactly 100, final strength 1%. To make 1 litre using the "to water" convention: 1000/101 = 9.9 mL concentrate plus 990.1 mL water.